dwightlooi

One word, commonality... better economies of scale, less parts in the supply chain, less parts to stock for supporting repairs. It adds up to a lot of money to have 4 engines of different displacement and components as opposed to 4 very similar ones.

Well, first of all, Caddy is already using Chevy small blocks. The CTS-V in both the current and previous generation does just that. Nobody seems to be complaining about CTS-Vs having 556hp LSA V8s instead of the 443hp 4.4 liter force-fed Northstar. The push-rod gives better cruise economy numbers than a DOHC V8. Aura quality at high rpm is a bit in a DOHC engine's favor, but valve train and induction noises can easily be turn into whispers with sound deadening which ought to be plentiful on a Caddy. This leaves the slightly higher vibrations from the mild end-to-end imbalance of cross plane V8s which is slightly worse in an engine of a larger displacement. Well, that's something you tackle with hydraulic engine mounts and all the other stuff.

GM has too many V8s in production... 4.6 (DOHC), 4.8, 5.3, 6.0, 6.2 and 7.0. There's no reason to have six different eight potters not to mention multiple variants for some of them. GM should standardize on one V8 block and heads. This is something which has been tried quite successfully in the V6 world by companies like Nissan (with its VQ35 V6) and it makes even more sense in the V8 world given the lower overall volume. Money saved through commonality and economies of scale can then be spent on technological content. I propose a 5.5 liter displacement in four different different guises. GM Gen V Small Block V8 - Basic Specifications Type: Cross Plane 90 deg V8, aluminum block & heads, watercooled Bore x Stroke: 103 x 82 mm Valvetrain: Single in-block cam, push rods, overhead valves, 2-valve/cyl Intake valves: 55 mm Exhaust Valves: 40.2 mm (Sodium cooled) Displacement: 5466 cc (333 ci) Variants:- Vortec 5500 Applications: Trucks and SUVs Features: Direct Fuel Injection Synchronous VVT Active Fuel Management (4-cyl deactivation) Long intake runners High Torque cam profile 11.3:1 Compression Ratio Power: 360 bhp @ 5600 rpm Torque: 395 lb-ft @ 3600 rpm Redline: 6000 rpm Fuel Type: 87 Octane Unleaded Gasoline Mainstream V8 Applications: Camaro SS, Caprice, Commodore HSV, Cadillac STS/DTS (Northstar replacement) Features: Direct Fuel Injection Synchronous VVT Active Fuel Management (4-cyl deactivation) Short intake runners Balanced cam profile 11.3:1 compression ratio Power: 400 bhp @ 6200 rpm Torque: 400 lb-ft @ 4800 rpm Redline: 7000 rpm Fuel Type: 87 Octane Unleaded Gasoline Performance V8 Applications: Corvette C7; ATS-V Features: Direct Fuel Injection Synchronous VVT Short intake runners High Power cam profile 12.2:1 compression ratio Power: 432 bhp @ 6600 rpm Torque: 423 lb-ft @ 5200 rpm Redline: 7000 rpm Fuel Type: 91 Octane Unleaded Gasoline (required) Extreme V8 Applications: Corvette Z06 / CTS-V / STS-V / Escalade-V Features: Direct Fuel Injection Synchronous VVT 4-lobe Roots Compressor w/air-water aftercooler Reinforced bottom end High Power cam profile 9.7:1 compression ratio Power: 580 bhp @ 6800 rpm Torque: 550 lb-ft @ 4800 rpm Redline: 7000 rpm Fuel Type: 91 Octane Unleaded Gasoline (required) Future Evolution (Gen VI Advanced Small Block) Cam-in-cam Dual VVT (independent Intake/exhaust cam phasing) 2-stage variable rocker-ratio control (VRC) Ionic Knock Sensing Beltless accessory drive (timing chain driven water pump; electric a/c compressor & pwr steering) Flywheel Integrated Generator/Starter (FIGS ;20hp) 24-volt Lithium-Iron-Phosphate electrical system User selectable Eco Mode with stoplight engine shutoff/restart & regenerative braking

Actually, Global Warming is complete and utter rubbish. There is none whatsoever, period. The evidence is overwhelming, but I will like to invite you to consider just five things -- five things which ought to get you started. (1) There is nothing abnormal about today's climate. The average global temperatures today, and at any point in the last three decades, is cooler than in the medieval warming period (9th~13th century) when the Norse explored Greenland and Genhis Khan united Mongolia. It is also cooler than during the Cretaceous when dinosaurs walked the earth and dozens of different inter-glacial periods throughout the planet's history. That's all before industrialization. What we are experiencing today can only be described as smack in the middle of historical norms. (2) In more recent times, global temperatures increased from the late-1800s to the late 1940s. From the late-1940s to the mid-1970s, global temperatures plummeted precipitously. Back then, the Al Gores of the world are yelling about the coming of an Ice Age. From the early 1980s through the turn of the millenium we saw again another mild warming spell. None of these collate in any shape or form with androgynous CO2 output or concentration which increased constantly from the 1800s to present day. Finally, from 2001 to present the planet has been cooling! Between the late 80s and today, there has been no net increase in average global temperatures. Please, do not simply believe me, check out NASA's satelite thermograph data yourself! (3) Historically, from ice core samples, global temperatures have never, ever, increased following an increase in CO2 concentration. The reverse is however is true. An increase in global temperatures always lead to an increase in CO2 concentration due to an increase in biological activity. Doesn't that make it difficult to claim that increase in CO2 concentration causes the warming? (4) The entire hypothesis behind CO2 causing Global Warming hinges on the claim that it is a green house gas and causes an accelerated greenhouse effect. If this is indeed happening, we must necessarily find hot spots in the upper atmosphere. Scientists know this and they have been launching balloons into the upper atmosphere for the last 30 years trying to find them. They didn't find an insufficient number of hot spots, or find in places they didn't expect. They didn't find any, period. (5) If we remove the Earth's atmosphere and simply run the radiosity equation with the planet and the sun. We'll end up with a surface temperature only ~33 degrees cooler than in reality. What that means is that that the entire atmosphere is only responsible for 33 degrees of warming. Now, note that water vapor accounts for most of it. Water vapor is 4% of the atmosphere, CO2 is 0.038% (it was about 0.028% in pre-industrial times). Water vapor accounts for 90~95% of the heat trapping effects of our atmosphere. CO2, CFCs and other trace gases combined accounts for 5~10%. Now, the Global Warming Alarmists like Al Gore are trying to claim the global temperatures may rise by 6 degrees unless we curb carbon emissions. In short, they are trying to say that increasing CO2 beyond the tiny 0.01% we managed in the last 200 years, thereby causing an infintesimal increase in a group of gases that only accounts for 5~10% of the total heat trapping effect of our atmosphere is somehow capable of causing 1/6th of the total warming by the atmosphere? In otherwords, increasing the concentration of 1% of warming capacity will result in 20% increase in the warming effect. It doesn't take a rocket scientist to realize that is total baloney.

Absolutely, agree. The front looks sharp. The side is clean cut. The interior is fabulous for the segment. The rear is untidy, soft and forgetable. The lines simply don't line up; the styling, or rather the lack thereof, is completely out of step with the front and sides of the car. I started a tread with a suggested re-styling of the tail-lights... here's the photo of what I think they could have done. I am keeping all the metal and bumper contours... this is really just a redo of the tail lights.

Chevrolet Cruze SS 2.0 DI VVT Turbo Honeywell-Garrett GT2259RS dual scroll turbo Air-to-water aftercooler 86 mm (bore) x 86 mm (stroke) 10.2:1 compression 11.8 psi maximum boost 91 Octane 270 bhp @ 6300 rpm (est) 228 lb-ft @ 2200~6000 rpm (est) Just a Cruze with an evolution of the current LNF engine with the objective of REDUCING but flattening maximum torque and reducing turbo lag. This is done by increasing compression, reducing boost pressures and using a small volume air-to-water aftercooler. Reducing maximum torque is actually good for a FWD car because it mitigates torque steer. In addition, the high-compression, lower boost setup is beneficial to cruise and part throttle fuel economy.

What makes you think that consumers want to spend $4000 more for a 30 MPG car vs say $4000 less for a 26 MPG car with more performance? Right now, 90% of buyers way towards the latter, only 10% of buyers do the Global Warming Coolaid.

Before we get carried away with doing everything possible to meet the 35mpg CAFE standard, it is wise to consider what happens if you don't meet CAFE intentionally or unintentionally. Trying to meet the CAFE standards is not a legal requirement. Not meeting CAFE standards does not prevent a company from selling cars. Not meeting CAFE standards carries a fine of $5.50 per 0.1 mpg per car sold. Each company actually has two CAFE numbers one for cars and one for trucks. One does not affect the other. The new standard does not kick in until 2016 -- the Obama administration for all its loony bravado wouldn't be there in 2016. The new standard is actually for 39mpg for cars and 30 mpg for trucks. It estimated by the clueless folks over at the Obama administration that it'll cost $1600 per car to meet the new CAFE standard. They nonetheless believe that government ought to make that choice of not the consumer or the manufacturer. Bob Lutz said it would cost $6000 per vehicle to meet the standard. Let's split the difference and call it $3800. Now, let's look at the numbers today. GM's passenger car CAFE numbers today is 31.3. The penalty of doing absolutely nothing is a fine of $5.5 x 7.7 x 10 = $423 per vehicle. This is 1/4th the $1600 the Obama administration thinks it'll cost to meet the standard. It is 1/14th what Maxmium Bob thinks it cost. It's 1/9th if we take the average of the two cost estimates. This is all assuming that fuel economy does not improve at all between now and 2016 in the natural, not particularly deliberate or extreme, course of improvement in automotive technology. Highly unlikely. Regardless, the ulimate choice is whether to add $400 to the price tag of a vehicle or spend four to fourteen times that to meet some arbitrary wet dream of some politician somewhere. If it's me, I'll simply incorporate the proven, inexpensive, non-performance robbing, technologies which benefit fuel economy as the come along and build cars and engines based strictly on consumer preference and let CAFE compliance fall where it may. Some $200~$400 added to the price tag is quite acceptable compared to going Hybrid across the board when only 10% of buys actually want to pay $2000~6000 more for a green and slow car which will not recover its hybrid premium for a decade.

Oh well... that's a whole other topic, but here's the long summary:- (1) Why Diesels rock. Diesel fuel does not carry more energy than gasoline. Diesel has an energy density of 46,300 kJ/kg vs 46,500 kJ/kg for gasoline (about the same). Even though diesel fuel is denser 0.85kg/liter vs 0.72 kg/liter for gasoline so the same mass of diesel fuel can be stored in 16% smaller a tank, that's something which may matter in a rocket or aircraft but not really tangible in a car. Diesel is better that gasoline mainly in two ways and it's all due to the way the diesel engine operates. The Diesel cycle (as opposed to the Otto cycle gasoline engine) does not have a spark plug and does not regulate air intake with a throttle body. A diesel engine compresses the air-fuel mixture to the tune of about 22:1. The mixture auto-ignites. The uniform burning from homogeneous auto-ignition and the high compression ratio enhances efficiency. In addition, a diesel engine basically suck in as much air as it can with no throttle regulation. Power output is governed simply by the amount of fuel introduced to the mixture. Diesel engines run very lean at idle, going richer and richer as you advance the gas pedal. The lack of a throttle butterfly reduces pumping losses and increases efficiency. (2) Why Diesels suck. Diesel engines plain out make less power than its gasoline counterparts all else being equal. An average naturally aspirated diesel engine of 2 liters may make about 75hp compared to 140hp in a gas engine. Ignition in a Diesel engine happens automatically from the mixture being at a certain pressure (hence temperature; pV=nRT) for a given period of time (it is not controllable by spark timing like in gasoline engines). This means that ignition happens too early at low engine speeds, with the mixture combusting before the piston reaches the top its compression stroke. This is why diesel engines knock and clatter at, or near, idle before smoothing out at about 1000~1500 rpms. As revs climb, diesel engines start to lose power as the ignition happens too late into the power stroke as the piston is coming down. If ignition happens at the bottom of the stroke an engine makes zero power, and way before that it starts to make less and less. Somewhere between 3000 and 4000 rpm ignition becomes notably late and diesels start to get noticeably out of breath. Usually by 4000~5000 rpm power falls completely flat which is why diesels have such low red lines. This is not just a characteristic shunned by driving enthusiasts, but also a problem because the narrow rev range means you need a lot of gears in the transmission to keep the engine operating between 1000 and 3500 rpm for instance. Ever wondered why 18-wheel big rig trucks with those massive 16 liter 6-cylinder diesels have 18-speed transmissions? Well, now you know why. Direct injection permits some rudimentary control of the ignition event by basically controlling when fuel is introduced! But this is not the same as precisely timing it with a spark event; it mitigates but does not eliminate the problem. With knocking and pinging being normal mode of operation, Diesels also need very stout bottom ends. In the old days it means a heavy iron block with big fat rods and journals. Even with today's "high-tech" aluminum diesels the engine is still heavier than a gasoline engine. Because a diesel engine runs lean at idle and at cruise, while going rich with the advancement of the throttle, it pollutes more in non-carbon related ways. This is particularly a problem during lean conditions (which is most of the time). Lean mixtures burn very hot and with lots of spare oxygen molecules sitting around. That produces lots of oxides of Nitrogen (NO, NO2, etc) which are hazardous to our health. Hence, diesels often need expensive nitrogen storing catalysts or Urea (yes, as in urine) injection to meet contemporary emission standards. In addition, because all the nitrogen storing catalysts are sensitive to degradation by sulfur contaminants, it is also important that sulfur is kept out of the fuel. (3) How turbochargers make a difference. Turbos basically help with getting the power density of diesel engines to the level of their naturally aspirated gasoline counterparts. A 2 liter turbo-diesel is now good for 140hp just like a decent 2.0 liter gasoline engine. Turbo-diesels have the same plumbing and intercooling complexities of force fed gasoline engines. But it has one advantage. The exhaust temperatures tend to be lower on diesel engines. This allows certain technologies like variable vane geometry turbochargers that tend to fail prematurely in gasoline applications to be used successfully in diesel engines. The lower EGT also makes it easier to place the turbocharger and the hot exhaust manifold in the valley of a Vee type engine compared to gasoline engines. The Duramax 6.6 for instance has the turbo in the middle of the engine with the intake plenums on the sides where the exhaust manifolds usually reside.

A turbo setup presents a myraid of issues. (1) Firstly, a turbocharger introduces turbo lag. On WOT it may not be bad especially if you use small turbochargers and modest boost levels. However, part throttle lag is quite pronounced even in such designs. (2) Secondly, the turbo extracts energy out of the exhaust which means it takes heat out of it. A catalytic converter downstream of a turbo takes a longer while to light making it harder to meet emission regulations. This is worse on twin sequential turbo setups which is why the 4.4 liter twinturbo V8s BMW just recently introduced are ditching their twin turbos for a single larger turbo. One way around the problem is to insert a pre-catalyst ahead of the turbo. Subaru does this on the turbo H4s, but this reduces turbo efficiency and performance (in the Subarus it meant the torque peak coming in at 4000 rpm instead of 2800 rpm). (3) Thirdly, with a turbocharger comes a whole spaghetti of pressurized plumbing to take air to the turbos, from the turbos to intercoolers in the front on the radiator and finally from the IC back to the intake. These take up a bunch of space, is often a source of leaks in older cars. They also contribute the turbolag almost as much as the inertia of the turbine and compressor wheels. This is due to the lag time attributable to bringing the pressurized volume up to the desired pressure. The bigger the volume, the worse the problem. Imagine pressurizing a basket ball and pressurizing a room, and you'll get the picture. The alternative is to use an air-to-water system which minimizes the pressurized volume and saves on all those big hoses. However, it also introduces a second water loop with its own pumps, radiators, heat exchangers, etc. (4) Lastly, while GM is certainly going to a 1.4 turbo for the Cruze for efficiency reasons, the economy advantages of a turbocharged engine is traditionally not very well established. For instance, an VW/Audi 1.8T engine making 150~170hp was not more more miserly on fuel than a typical 2.2~2.4 liter engine of a similar output. Their 2.7T with 250hp was not more economical than a 3.2~3.5 liter engine with 250hp either. The 300hp twin turbo I6 from the BMW 335 is not more economical than a 3.6 liter DI V6 from GM or a 3.5 DI V6 from Toyota also making about 300hp. One can make a reasonable argument that 140hp with 40~42 mpg which the Cruze is shooting for can be had with a 1.4 turbo or with a 1.8 liter NA engine with DI and part time Atkinson cycle (ala the Civic's R18A). This is mainly due to the reduced compression ratio and the inability to utilize resonance charging with the (by now) well honed art of tuning intake runner lengths and plenum volumes. The biggest advantage really is that for a given hp, these turbo engine tend to have better low end torque. The disadvantage is that the cost more than an NA engine with similar output and/or economy. As far as a twin turbo V8 goes, you can probably go down to about 3 liters and still make 420hp. It'll not cost less than a high reving 4.0 NA and certainly not less than a 5.5 liter Pushrod. It may not be any lighter or take up any less space. It may not be as reliable or as responsive off boost. Finally, it may not be more economical on fuel. If you really want a turbocharged engine in the Vette, it'll make more sense to drop two cylinders and go to a turbo six. The new V6 S4 picked up fuel economy not because it went to a smaller displacement and a supercharger, but because it went from a V8 to a V6 reducing a bunch of frictional loss by eliminating two cylinders, two journals and 8 valves. I had once suggested that... a turbocharged version of the 4.2 liter DOHC Inline-6 making about 420hp using one turbo (about 10 psi of boost and 10.5:1 compression). Afterall, the Vette started life with a six. But, I didn't recall many liking the idea of an six cylinder Vette.

Actually, a SIBC (Pushrod) engine does not have higher torque than an DOHC engine of equal displacement. The DOHC engine usually makes more torque as well as power. About 8~12% more torque and 10~40% more power. But, that's besides the point. The point is that while a pushrod engine needs to be bigger in displacement to match the output of a DOHC powerplant, in can do so without being physically bigger or heavier than the smaller displacement DOHC engine because it has much smaller, simpler and lighter heads as well as much simplified valve train parts. The simplicity, of course, makes it cheaper to manufacture or service as well. In addition, because of the lower level of internal friction and increased low rpm torque from the increased displacement affording taller overall gearing, it is usually also lower in fuel consumption. These are the reasons the pushrod design was invented in the first place -- it actually came after the advent of SOHC and DOHC designs in the 1930s. The problem with SIBC engines are two fold. The first is the heavier actuated mass of each individual valve -- due to the long pushrod and larger valve diameter -- limits civility at higher rpms and ultimately forces a lower ceiling on revs before valve float and other issues become insurmountable. In passenger cars this translates into a lower level of perceived refinement. In race cars, it limits ultimately permissible revolutions and reduces durability. The second being that in many countries, tax on a vehicle is based on its displacement not fuel economy or anything else. Hence, using a larger displacement engine makes the car more expensive regardless of whether it uses more or less fuel.

Q&A Q: Why did I start this thread instead of continuing a previous thread also on C7 engine options? A: Because this is about which V8 for the C7 assuming we are set on a V8, that was about whether the Vette should get a V12. Q: Why did I compare a 4.0 liter DOHC with a 5.5 Pushrod? A: The idea is to get to ~420hp. Also, a 4.0 liter DOHC will weigh about the same and take up about as much space as a 5.5 Pushrod. Q: Why a 60 deg DOHC V8? A: Because the idea is to minimize R&D, as well as share most components and the manufacturing line with the existing 90hp/liter liter LF1 60 deg V6 (3.0 270hp). Besides, a more compact 60 degree V8 is required if the engine is to fit in the same width as a 5.5 liter pushrod V8. A 60 degree engine won't be even fire, but neither is a flat crank V8. In a sports car, that slightly off-beat pulse is perhaps even a plus. 60 deg V8s are not horrible or all that rare... the Taurus SHO 3.4 V8 and the Volvo 4.4 V8 are both 60 degree designs. Q: Where did the fuel economy estimates come from? A: The 5.5 pushrod's estimates come from assuming a slight improvement over the current 6.2 liter LS3 engine. This assumption is based on incorporation of an 8-speed dual clutch transmission, taller cruising gear ratio, higher compression, Direct Injection, Cylinder deactivation and a lower displacement. This accompanied by about 10% lower weight and slightly smaller size projected for the C7 led me to estimate a 1 mpg improvement in city driving and a 2 mpg improvement in highway cruising. I don't think they are unreasonable estimates. If anything they are a bit conservative. Q: Why did I assign lower fuel economy numbers to the DOHC engine? A: Because DOHC V8s of today have worse economy numbers than pushrod V8s today. The reasons are mainly that they have higher internal friction due to having twice as many valves & guides, four times as many cams and a much longer serpertine cam drive chain. In addition, because DOHC engines make a given horsepower with less displacement, less torque, but at higher revs, they also tend to be geared to keep revolutions higher. This often increases pumping losses more than the reduced displacement saves. For example... The 6.2 liter Camaro SS posts 16/25 with an automatic, the 6.3 liter C63 AMG posts 13/20 mpg, the 4.0 liter M3 posts 13/20mpg. The Camaro weighs 3859 lbs, the C63 logs 3924 lbs whereas the M3 tips scale at 3726 lbs.

Which engine Corvette fans will like to see in the next corvette... GM's next generation 5.5 liter Small Block push-rod V8 with DI and AFM, or a 60 degree V8 derived from the high specific output 3.0 liter DOHC V6 engine?

The problem with going all electric is three fold:- The battery is the single most expensive component in the car. The battery is the single heaviest component in the car. The battery is the single bulkiest component in the car. Hence, by doubling the battery capacity and dropping the gas engine you'll get a car that costs about 50~75% more, has less than twice the range and is about half a ton heavier. The range factor means that you get a 60~80 mile car -- a strict commuter. The weight factor means that performance just went down a couple of notches. Not to mention, you just doubled already astronomical the battery replacement costs when it comes time to swap out the unit 5~10 years from the car leaving the factory floor. It's not an easy sell as a practical vehicle -- cost too much and goes too little rather slowly. This problem has plagued electric vehicles since the turn of the last century. Basically, it revolves around batteries having horrible energy densities and being rather expensive and short lived. Advancement in battery technology from lead-acid to Nickle-Cadmium to Metal-Hydride to Lithium Ion to Lithium-Iron-Phosphate, took us from horrible densities to pretty bad densities, from rather toxic to not so toxic, from very short lived to pretty short lived. What it hasn't done is bridged the energy density gap of over two magnitudes between batteries and hydrocarbon fuels. Batteries need to store 100~250 times more, and I do not believe there's a chance that chemical batteries ever will! Let's look at the numbers shall we? Energy Densities ------------------- Joules/kg --------- Joules/liter Unleaded Gasoline - 46500 ------------- 34300 Low Sulfur Diesel - 46200 ------------- 37400 Lo-FeP Battery ---- 330 --------------- 790 Li-Ion Battery ---- 700 --------------- 850 Ni-MH Battery ----- 250 --------------- 490 Lead Acid Battery - 140 --------------- 360 As far as the solar panel goes, it's a worthless gimmick to put on the roof of a car. A good solar panel makes about 110 watts per square meter in peak sunlight. Without a moon roof or any other annoyances on the roof, you have about 2 sq-m worth of usable space. That's 220 watts in peak sunlight. On a cloudless summer day you get about 6 hours equivalent of peak sunlight over the course of the day. That's about 1.32 kW a day assuming you park the car right in the middle of the lot with zero shade from dawn till dusk. It'll take about 12 days to recharge the 16kWH battery pack in the standard Volt that'll take you 30~40 miles. That's all assuming the height of summer, no cloudy days and no shade ever befalling on the car. More realistically, the solar panel will get you one recharge every month in summer, maybe one every two months in spring/fall and struggle to make one charge over the entire winter season. That's about as useful as a cage full over hamsters with pinwheels except you don't have to feed them.

If it's me, I'll do it this way... Battery pack remains the same 16kWH module to keep costs and weights reasonable. Front Motor = Volt motor (no change) Add a second 150hp motor onto the rear axle. The 71hp 1.0 liter engine is upgraded to a 1.4 140hp liter turbo engine being used by the Cruze. Generator capacity is likewise doubled. This will give the car about 300hp and pretty lively performance. Like in the Volt, the engine will not attempt to recharge the battery to capacity in the interest of battery life. Instead, it'll provide the primary electric source once the battery drains to a certain level. The battery then provides temporal acceleration power boosts only when needed like a conventional parallel Hybrid. Unlike the Volt, the drive train can be programmed to turn the engine on whenever charge levels fall below 40% instead of 30% and recharge the battery when it reaches 25% to 40% instead of 30%. This helps give the vehicle a deep charge cushion when the driver stomps on the gas after the battery drains past the engine on level. Given the increased minimum charge level, higher weights and more powerful motors, while retaining the same battery pack, the Converj will probably have an electric only range of about 30 miles instead of 40 miles. It'll however be a much faster car with a more entertaining driving experience. 300hp with 546 lb-ft at zero rpm delivered to all four wheels is no joke. It'll be fun. And because it is fun and a Caddy, it can also be expensive. Price it anywhere below the Model S and it'll have it's little niche amongst the Global Warming believing Coolaid Drinkers with some bucks to spare.

I think they need to simply keep it simple and small. Try MacPherson Struts in front and Chapman Struts in the back simple. Reduced mass and proper tuning does more for handling than double wishbones and five link arrangements. Doubters should drive a Boxster or Cayman one day... its not bad... really.

The Integra did not go away. It was replaced in 2002 (as a 2003 model) with the RSX after an uncharacteristically long (for a Honda) 8-year run. The RSX is still the Integra in other markets, but was given the RSX nomenclature to bring it in line with the rest of Acrua's lineup which do not have verbose names. The K20 powered RSX is a 2700 lbs car. Not appreciably heavier than the 2643 lbs outgoing B18 powered model. The RSX is still on sale today and it is still available with the 8000 rpm 200 hp engine if you want it. No, it is not a particularly expensive car to insure nor is the old Integra for that matter. The Camaro is HEAVY because it is a Zeta and it is a HUGE car. It sits on a full size, RWD, sedan platform designed to support the Holden Commodore, Statesman and Caprice. It is like building a sports car on a Crown Vic (Panther) platform -- well maybe not quite that bad but you get the picture. Whatever the Alpha turns out to be, it'll be smaller and it can be substantially lighter. And, if has the cabin the size of a 2001~2006 C-class or 1992~1999 3-series it'll be plenty for the kind of shoppers it targets. Those who want a bigger car can always be shown the Zetas and Sigmas.

This is not really true. Other than for the requiring airbags in the 90s, government "safety" regulations haven't changed much over the past decade and a half here. In Europe there is the minimum bumper height nonsense, but apart from that there hasn't been legislative requirements that cars have to be able to with stand crashes much better than they did in the 90s. What we have seen is a great deal of voluntary advancements in terms of crash safety. If you build a new car today with exactly the same impact safety as a 1994 Integra, it won't earn a 5-star crash rating. But it also won't be illegal to sell in the USA. If you raise the bumper height it'll be OK in Europe too. A Lotus Elise is very light and quite under protected against side impacts and front offset intrusions. It is nonetheless a completely legal car to market in the USA. Regardless of all of that, it is also quite untrue that cars have to be much heavier to meet today's safety expectations (mandated or otherwise). The 2006 to present Honda Civic is 2750 lbs. That is not that much more than the 2400~2600 lbs of the previous two generations. Most of that comes from the fact that the current model is a much bigger car. So big in fact that Honda has to have a separate Civic model for Europe and the "Fit" to cater to customers stateside who feel that the Civic is too big a car for their preference. I am not against safety, but one also has to recognize that tank like crash safety performance is not required by law and perhaps should not be the #1 priority in a sporty car. How many customers will shy away from a sports car because it has a 3.5 stars crash rating instead of 5 stars? On the other hand, a heavy, under performing and somewhat sluggish handling car may turn away good number of enthusiasts. There may even be a niche market for cars which do not even hide the fact that they trade safety for performance, style or driving dynamics -- hey if that isn't true nobody will buy Motorcycles or ride one without a helmet (in states that permit it). For a mainstream product like the Camaro targeted at young, driving enthusiasts. There can and should be a balance struck between lightness and safety, and it shouldn't be either taken to the extreme. This really is is a choice here for the designer to make; an oppressive safety standard mandating 4000lb designs is a myth.

The Challenger a little bit, but not anywhere near the degree of the Camaro. The Mustang? Not at all.

I did not drive the Camaro, but I did see the car person. I give the cabin a B-. It's not blatantly cheap like the classic F-bodies or 1990s GMs. But it is a vast expanse of plastics and not all of a matte sheen. Some parts of the dash has the dreaded "armorall" sheen which is so typical of GMs in the 90s but which the General has done a good job of shedding in recent years. The grey plastics and fat black bezel of the stereo and HVAC, while unique to the Camaro, looks cheaper and less refined than the corporate standard issue stuff in the Malibu, the Kappas, etc. The Shift knob has a shiny patina which look like it has been well used although this is a brand new vehicle. Driving position is barely OK but not great for me; it will be a problem for anyone of a smaller stature. I like to drive with very little seat back recline and with comfortably bent arms and knees. With the steering pulled as far forward as possible, I find myself pushing the seat further forward than I like. The car also has some dubious decorative elements. The chrome surrounds of the tail lights actually looks (cheap) and makes the production car less pretty than concept car without it. I am not sure I buy the non-functional features like the fake hood scoop or the three vertical indentations ahead of the rear wheel well either. The 20" wheel looks heavy and somewhat contrary to my preference for the the biggest contact patch but only as much wheel size as it takes to clear the calipers (my all time favourite has always been the 225/45 and 255/40 R17 sizes) But overall, it is not a bad looking car if you are into the modernized-retro look and don't mind a few gimmicky bits here and there.

Well, yes and no. It depends on what you are after. For any given bore area, having 4-valves allows you to flow more air. This in turn allow you to burn more fuel and hence make more power. 5-valves do even better (albeit slightly) and some designs combine a 5-valve head with a narrow bore and long stroke to achieve the desired balance between energy recovery from a long stroke engine and adequate breathing to not be too labored at higher revolutions. The VW/Audi 1.8L (I4), 2.8L (V6) and 4.2L (V8) 5-valve engines (1997~2005) comes to mind. However, one has to understand that 4-valves is not a free lunch and its advantages are largely beneficial only at engine revolutions above what is typically experienced in car cruising down the freeway or puttering placidly around town. The disadvantages of using 4-valves is the additional valve train friction, increased engine mass from larger heads to accommodate the overhead single or (especially) dual cams. In addition, increased flow cross sections also reduces intake velocity which is detrimental to fuel-air mixing leading to increased emissions and reduced power from incomplete combustion unless it is carefully addressed. The increased flow cross section of the valves does not do much for you performance wise until around 4500~5500 rpms (depending on the design). In the early eighties, when manufacturers first went to 4-valve heads in mass produced engines, many designs like the Toyota 4A-GE and 3S-GE had to resort to separate intake tracts for each valve and butterflies to block off half of them at lower engine speeds to promote intake swirl and complete combustion. In general, the 4-valve engines were weaker than their 2-valve counterparts at lower engine speeds and were no more economical. They did however provide higher output for the displacement. Overtime, manufacturers narrowed the intake port sizes, increased runner lengths and in general toned down their 4-valve designs such that they no longer required complicated implements to run properly from idle and up. However, many engines also no longer realize the performance potential of their 4-valve configuration. For example, a turn of the millennium Toyota 1MZ-FE engine found in the Camry made 192hp @ 5400 rpm out of 3.0 liters (~64 hp per liter). It no longer has the V-RIS swirl promotion system but has relatively mild cams and narrow intake tracts instead. At 5400rpm, a 2-valve head would have been adequate to provide the necessary flow for a similar output. The reality is that from an economy or performance standpoint, if you are aiming to produce an engine with less than ~70 hp/liter you really don't need a 4-valve design. The LS3 engine in the current Corvette and Camaros is a 68~70hp/liter engine and does NOT in any way sport a radical tune. If you do elect to use a 4-valve design, you pay for it in terms of higher frictional drag (which may cost you cruising economy), greater complexity, higher cost, more weight, bigger size, etc. And, you get paid back tangibly only terms of more refined engine noises. So really, the million dollar question is whether that is your first and foremost priority!

The art of building the most economical engine:- To build the most economical engine in any given displacement you will want to do the following:- Build the biggest engine with the fewest cylinders. Maximize the Compression Ratio. Use as little cams and valves as you can*. Incorporate VVT. Make it an Atkinson or Miller Cycle. Give it a resonant long intake runner set optimize for the mild acceleration band. Incorporate Direct Injection. Gear the transmission to produce the lowest acceptable RPMs at 60 mph. Ensure that it runs on 87 octane. * Meaning you'll use an SOHC 2-valve arrangement for an inline engine or Pushrod 2-valve arrangements for a Vee engine. Eg. If you want the most economical 2.0 liter engine, you'll make it a Direct Injection Inline-3, top it with a SOHC 2-valve head with co-axial dual VVT, give it Atkinson cycle cams, 11.3:1 compression ratio, give it long intake runners which produces resonance charging at 2000~3000 rpm and gear it such at it turns at 2000 rpm at 60 mph (barely able to sustain that speed) without a transmission downshift. Eg. If you want the most economical 4 liter engine, you'll make it a Direct Injection V6, top it with a pushrod 2-valve head with co-axial dual VVT, give it Atkinson cycle cams, 11.3:1 compression ratio, give it long intake runners which produces resonance charging at 2000~3000 rpm and gear it such at it turns at 1400 rpm at 60 mph (barely able to sustain that speed) without a transmission downshift. Remember, we are not talking about performance here, or civility, or anything else. Just pure Fuel Economy.

I think there is a misconception that smaller displacement equals better economy or that more valves equal better economy. This is not true, in fact sometimes the reverse is true. For instance, when you drop displacement from say a 3.6 liter V6 to a 2.8 liter V6 you have to ask yourself what happens in the process? Assuming that both engines have the same valve train layout not much has changed there -- same number of sprockets, same number of bearings, same number of cam lobes, same number of followers, same number of valves stems rubbing against the same number of guides. Hence, valvetrain friction remains roughly similar. Now the bores have probably shrunk a little so you have a reduction in wall friction there and the amount of air you are pumping in and out of the engine is reduced so you have reduced pumping losses. The overall improvement in economy is really from these areas and it is slight. It is so slight in fact that because the lower displacement engine also has less torque and power, and is frequently given lower gearing to get it off the line smartly this change in gearing often cancels out the economy gains. More effective is a reduction in cylinder count and making the biggest displacement from the smallest number of cylinders as you can. Now, you move to forced induction. This is also a mixed bag. A turbocharger gets you additional power from the same engine size, but it also does two things detrimental to fuel economy. The first being that it drops compression ratio. Usually 1 to 2 points. Also, it eliminates whatever fancy intake work you can otherwise implement to achieve resonance charging. In most instances, when you move from a bigger engine without turbo(s) to a smaller one with turbo(s) making the same power, you do not gain fuel economy with all else being equal. When you see a gain, it is usually because you moved from an engine with more cylinders to one with less cutting down on frictional losses. Good examples are Audi's 4.2 liter V8 vs 3.2 liter turbo V6 or GM's own 3.6 liter V6 vs 2.0 liter I4 -- all engines making similar power but the turbocharged unit has less cylinders, less valves, etc.

I don't think the Pushrod 2-valve vs DOHC 4-valve contest is one over which one is more "advanced". Advanced is a subjective term. The pushrod engine was invented after the overhead cam engine. However, the average DOHC 4-valve design currrently in production also has more technological content such as variable timing, variable valve lift, direct injection, variable intake mannifolds, coil on spark ignition, etc. (all of which an OHV design can also incorporate). But, all of that are irrelevant. What are relevant are these:- Pushrod engines can achieve a higher power-to-weight ratio. Pushrod engines can achieve a higher power-to-size ratio. Pushrod engines can achieve a higher power-to-cost ratio. DOHC 4-valve engines can achieve a higher power-to-displacement ratio. DOHC 4-valve engines can achieve a higher degree of NHV refinement. DOHC 4-valve engines can achieve attain higher maximum engine speeds. Fuel economy is roughly equal for a given level of performance.

Because they were after refinement and consumer perception in that segment more than anything else. Let's look compare apples to apples for a minute... The 3.9 liter Pushrod V6 made 240hp in the G6. The 3.6 liter high feature V6 (without direct injection and its accompanying compression ratio bump) makes 252. Is that such a huge difference? If the 3.9 had been an aluminum block it'll be smaller and lighter than the 3.6 DOHC too. You can probably get a 4.2~4.5 liter Pushrodder to fit in the same exterior envelop and tip the scales at the same weight as a 3.6 liter V6. In the case of the V8 the difference is even more pronounced. In general, with similar materials and construction, a 6.2 liter pushrod is about the same mass and size as a 4.2 liter DOHC V8. In any case, when it comes to the Corvette, the DOHC V8 or Turbo-6 is not particularly appealing because it buys no additional performance at an increase in cost. In terms of prestige and consumer perception, it doesn't stand out either. In fact, one can argue that it offers less appeal since the small block like the evolution twin has its swarm of fans who loves it's slightly rude character. Which is why I feel that a DOHC V-12 may make more sense than a DOHC V8. When it comes to economy, the biggest factor is vehicular weight. The reason being that it takes power to accelerate mass and it takes fuel and air to make power. Next comes the gearing which is especially important at cruise speeds. Which has more wasted energy? A 6 liter 8-pot at turning over 1600 times a minute or a 4 liter 8-pot making 2400 revolutions? In third place comes the frictional losses within a specific engine and its breathing losses. Here, a 2-valve push rod has lower frictional losses, whereas a 4-valve DOHC has lower pumping losses. All else being equal, at cruising speeds and loads, the push rod has the advantage, at power peak the DOHC has the advantage. However, since the push rod engine tends to also be bigger in displacement it is about a wash at cruise with the advantage clearly going to the DOHC engine at the power peak. What does these all add up to? Well, a light vehicle with a tall gearing can be just as economical as a heavier vehicle with a shorter gearing even if the former has a much bigger displacement motor and a push rod valve train. Even when the vehicles are the same approximate mass, the difference is less significant than most people believe. Case and point? Chevy Corvette -- 6.2 liter 432hp OHV 2-valve V8 = 16/26mpg (City/Hwy) Chevy Camaro 3.6 V6 -- 3.6 liter 300hp DOHC 4-valve V6 = 18/29mpg (City/Hwy) Chevy Camaro SS -- 6.2 liter 420hp OHV 2-valve V8 = 16/24mpg (City/Hwy) Mercedes C55 -- 5.5 liter 362hp SOHC 3-valve V8 = 16/22 mph (City/Hwy)* Infiniti G37 -- 3.7 iiter 330hp DOHC 4-valve V6 = 18/26 mpg (City/Hwy) Honda Accord EX V6 -- 3.5 liter 271hp SOHC 4-valve V6 = 19/29mpg (City/Hwy) Toyota Camry LE V6 -- 3.5 liter 268hp DOHC 4-valve V6 = 19/28mpg (City Hwy) * I get about 18mpg on the average in combo local and feeway driving to and from work