Is GM missing the boat?

[cmattson]

With gas prices rising as high, if not higher than they were last summer and with VW's Jetta bluetec 2.0TDI rumored to get 40/60 mpg, I'm wondering if GM is missing an opportunity. I know that diesels cost more - and GM is skeptical that people would be willing to pay that premium, but consider this:

If you drive 15,000 miles/year and your 4cyl car averages 30mpg, you'll consume 500 gallons of gas. Prices in my neighborhood for gasoline just jumped to $3.39 today.. so that's $1695/year. If you get 60mpg in your TDI, you'll consume 250 gallons of diesel. Current prices for diesel here are $2.79/gallon, which gets you to $697.50/year. You are a 2 diet coke's away from saving a cool grand -- in just one year. That oil-burner pays for itself pretty darn quick, doesn't it? Now factor in that the diesel would be cheaper to maintain over the long haul and that it's offering you a much better driving experience (way better torque). How about the idea of GM offering a high mpg vehicle? You want to change people's perception of what GM can or is willing to produce? Here's a golden opportunity to do just that.

GM's either playing this really close to the vest, or they are moving very cautiously (read: slow) on this one. Seeing how long it's taking to get those 6-speeds into their cars and trucks, I think I know the answer to this one. Somedays it's really frustrating to be a GM fanatic.

Edited May 18, 2007 by cmattson

[Sixty8panther]

YES!

I want a 7-speed manual, pillarless hardtop, Solid rear axle 5th

gen. Camaro powered by a Duramax-Diesel twin-turbo V16

That way I can get almost 13mpg in the coolest car of the 21st century.

[the_yellow_dart]

Was it ever worth it?

Was there all that much to gain?

Well we knew we missed the boat

And we'd already missed the plane

[balthazar]

Numbers look fine, but don't forget to figure in the initial price tag for the diesel.

Friend of mine is running an old rabbit on veggie oil- 1 year and counting: fuel cost $0.

[cmattson]

That's kinda the point I was making with the numbers: the even if you had a $3k premium on the engine, you'd break even in as little as three years. Everything after that point is pure benefit.

[CSpec]

I'm not sure why everyone on this site is infatuated with diesels. They're gruff and grumbly and noisy, plus they are quite expensive and filling up is tricky.

I guess it doesn't really matter since US emissions regulations won't allow them without a huge price hike...

[Flybrian]

How is filling up a Diesel car tricky?

[dwightlooi]

Numbers look fine, but don't forget to figure in the initial price tag for the diesel.

Friend of mine is running an old rabbit on veggie oil- 1 year and counting: fuel cost $0.

Actually, I am sorry, but they do not.

In general, with a vehicle of the same weight and doing the same typical duty, a TDI is not going to be twice as efficient. At best it is about 20~40% more efficient. And this is assuming we are not expecting the same performance.

For instance, the current Jetta TDI is rated for 36/41 MPG, whereas a Jetta 2.0 turbo FSI is rated for 25/31mpg. And remember this is not exactly a fair comparison in that even though the displacement of the two engines are quite close (1.9 vs 2.0 liter) and both are force induced, one is a 100 hp mill whereas the other is a 200hp powerplant. I am SURE that if you replace the Gasoline FSI engine with another engine offering similar acceleration performance to the 100 hp diesel, the difference will be even narrower. The overall efficiency in terms brake specific fuel consumption (fuel use / power; per unit time) between a diesel and a gasoline engine is about 20~25%.

To answer the "why not offer miserly diesels as an option?" question, the one question a person has to ask is why isn't GM or any other car manufacturer dropping in small, underpowered gasoline engines into the cars or at least offering that as an option? I mean lets say that instead of a 2.4 liter Ecotec, you get the option to opt for a 1.6 liter Ecotec. That'll yield efficiency gains as well, for ZERO extra dollars and in fact probably a few bucks less. Sure, the car will be slower, but so will a typical diesel optioned car! I think the answer is simple. The typical consumer doesn't want it -- while they may bitch about $3+ gasoline (which really is quire cheap compared to anywhere else in the world; Europe is ~$6.50 for instance) they really still want performance and refinement more than gas savings when making a purchasing decision. And, those really "green" types will buy a Hybrid not a diesel. This is more of a lifestyle decision and "green" statement rather than an economic decision because today's Hybrids DO NOT MAKE ECONOMIC SENSE*.

* Let's say you drive a Prius with 51/60 MPG (say 55.5 avg) vs a Corolla 32/41 mpg (say 36.5 avg). If you drive 12,500 miles a year (blue book yearly zero value adjustment allowance), the fuel use difference is roughly 12,500/55.5 - 12,500/36.5 = -117 gallons. At $3 per gallon, thats ~$352 per year. Given the fact that the price difference between a comparably equipped Prius and Corolla is $6000 (~$22000 vs ~$16000), it'll take you 17 years to recover your $6000 investment in the Hybrid drivetrain. Heck, even at $6 per gallon it'll take you 8.5 years to recover that $6000. And, we are assuming you won't have to fork over extra money for a thousand dollar battery somewhere along the way. This is why Hybrids today are not economic vehicles, they are a life are enviromental choice and image statements. If buying and driving one makes you feel better or makes you look better in front of your "green" friends, by all means buy one. But don't tell me you are buying one to save money on gas, because if you really think so you are a total idiot!

Plus, while every station offers gasoline, #2 diesels are only available in minority of gas stations. This is an inconvenience.

Edited May 19, 2007 by dwightlooi

[Drew Dowdell]

Plus, while every station offers gasoline, #2 diesels are only available in minority of gas stations. This is an inconvenience.

One can drive 700 miles on a single tank of diesel in a Jetta TDI. That's across the entire state of Pennsylvania and back. If you can't find a diesel station in that amount of time, then yea, you'd have a valid point.

Secondly, I don't even own an E85 capable vehicle, yet I know where all the E85 stations in town are for when I do buy an E85 vehicle. It's a lifestyle choice. Someone who wants a diesel will learn who in their area carries it and who doesn't.

Thirdly, you're right, you should compare similarly powerful engines. Compare Cadillac's new 2.8 turbo diesel in Europe to the current 3.6 and get back to us.

[cmattson]

Part of my original point was that diesel fuel is (currently) cheaper than gasoline -- by about 18% where I live -- which only compounds a diesel's benefit. One other thing to keep in mind is this: paying a premium for a diesel engine is something that you'd likely recoup a portion of upon resale.

[Sixty8panther]

It's not about the fact that the diesel fuel is cheaper... it's that you use a lot less!

[dwightlooi]

Part of my original point was that diesel fuel is (currently) cheaper than gasoline -- by about 18% where I live -- which only compounds a diesel's benefit. One other thing to keep in mind is this: paying a premium for a diesel engine is something that you'd likely recoup a portion of upon resale.

Actually, the reverse is probably true. The fact that diesels are not widely offered is because diesels are not widely wanted by car shoppers. When it comes time to sell the car used, you may find that 9/10 buyers otherwise interested in the size or model of vehicle won't even call once they see "diesel" on the for sale listing. Lower demand means lower prices, thats market dynamics. The same goes for say a minivan with a stick-shift for instance, possibly upwards of 99% of minivan buyers don't know how to or don't want to row a stick, that reduces demand and hence price of the vehicle.

[Intrepidation]

YES!

I want a 7-speed manual, pillarless hardtop, Solid rear axle 5th

gen. Camaro powered by a Duramax-Diesel twin-turbo V16

That way I can get almost 13mpg in the coolest car of the 21st century.

Solid axle

[dwightlooi]

Solid axle

Actually, a solid axle (live axle) is not all bad. Let's put it this way...

(1) A live axle maximizes traction when the car is accelerating (and to a lesser degree braking) in a straight line. This is because all independent suspensions do not keep the tire's contact surface parallel to the ground when compressed (or extended). Instead, the tires gain or lose camber when compressed or extended. The whole purpose of the double wishbone or multilink setup is to control the change in camber such contact patch on the outside tire is maximized when the car rolls during cornering. In short, all else being equal, live axles are FASTER in a drag race because it offers superior traction.

(2) When cornering, it is entirely possible to keep a live axle planted and simply roll the body. In fact, when the roll stiffness is optimized for performance and the suspension is sufficiently firm there is no difference between the steady state corning grip between a live axle and an independent rear suspension.

(3) The advantage of an independent rear suspension is that a high level of cornering grip can be achieved without a lot of roll stiffness or overly harsh rides. On top of that they tend to be much less twitchy when disturbed while loaded -- such as when you hit a mid corner bump. Overall ride quality is also better because the IRS has much less unsprung mass than the live axle.