Opel Reveals A New 1.6L Turbo

Sweet for Cruze and Sonic.

I call for an Encore....

base malibu too?

Encore and Verano need that, and optional for the Cruze. Then Buick at least has some separation from Chevy, rather than having the same powertrain.

Shoot I plumb forgot about the Buicks. Yeah, those too.

This will be sweet in the Encore.

I would guess that any vehicle that is Opel based would be first in line to get it. So in the US that means Encore, Verano, and Regal.... though I believe Regal to be least likely to get it in the current generation.

I generally don't favor turbocharged setup with much higher torque figures than hp numbers. There is only one conclusion you can draw from such figures, and that is that the turbocharger is undersized and over boosted.

Let me explain... 206 lb-ft is 206 hp at 5252rpm. What that means is that the power peak arrives at some engine speed lower that. Assuming a flat torque plateau the power peak is probably around 4300 rpm. You can also get 168 hp if you boost the engine to say a mere 160 lb-ft but carry it to 5500 rpm. Generally speaking the effective mass air flow in both power peak instances are about the same and generally speaking the same turbine/compressor pairing would be used in both. The only reason the engine is not about 220 hp @ 5500 rpm is because the selected turbo is too small and runs out of airflow capacity above about 168 hp.

There are two reasons why taking an engine with a very small turbo to relatively high boost at lower rpms then having to back off quite early (in the 4000s) to avoid overspeeding the turbo is not ideal. First of all, a 168hp @ 5500 rpm / 160 lb-ft @ 1500~5500 rpm engine is far more linear and enjoyable to drive. Turbolag getting to 160 lb-ft will be significantly less than getting to 206 lb-ft, also the engine won't feel like it's running short of breath early in the mid-4000s. A 168 hp @ 4300 rpm / 206 lb-ft @ 2300~4300 engine feels like a diesel!

The second reason is one of efficiency. A significant factor affecting fuel economy is the compression ratio of the engine. This is because the compression ratio in an Otto cycle is it's expansion ratio and a larger expansion ratio extracts more energy from each ounce of fuel burned. If you take an engine to about 100 lb-ft / liter you can have a 10.5~11.0:1 compression with direct injection with a boost pressure of about 10~11 psi. If you want to take the engine to about 130 lb-ft / liter you need about 18 psi of boost which means your compression (even with DI) needs to go down to about 9.0~9.3:1. That in and of itself is worth about 10% mpg (3~4 mpg) in a small engine in a small car.

Small turbo, high torque, low hp is the worst of both worlds. It has the increased lag and reduced economy of an engine with a larger turbo and about 130 hp/liter, while not having the power and performance.

I generally don't favor turbocharged setup with much higher torque figures than hp numbers. There is only one conclusion you can draw from such figures, and that is that the turbocharger is undersized and over boosted.

Let me explain... 206 lb-ft is 206 hp at 5252rpm. What that means is that the power peak arrives at some engine speed lower that. Assuming a flat torque plateau the power peak is probably around 4300 rpm. You can also get 168 hp if you boost the engine to say a mere 160 lb-ft but carry it to 5500 rpm. Generally speaking the effective mass air flow in both power peak instances are about the same and generally speaking the same turbine/compressor pairing would be used in both. The only reason the engine is not about 220 hp @ 5500 rpm is because the selected turbo is too small and runs out of airflow capacity above about 168 hp.

There are two reasons why taking an engine with a very small turbo to relatively high boost at lower rpms then having to back off quite early (in the 4000s) to avoid overspeeding the turbo is not ideal. First of all, a 168hp @ 5500 rpm / 160 lb-ft @ 1500~5500 rpm engine is far more linear and enjoyable to drive. Turbolag getting to 160 lb-ft will be significantly less than getting to 206 lb-ft, also the engine won't feel like it's running short of breath early in the mid-4000s. A 168 hp @ 4300 rpm / 206 lb-ft @ 2300~4300 engine feels like a diesel!

The second reason is one of efficiency. A significant factor affecting fuel economy is the compression ratio of the engine. This is because the compression ratio in an Otto cycle is it's expansion ratio and a larger expansion ratio extracts more energy from each ounce of fuel burned. If you take an engine to about 100 lb-ft / liter you can have a 10.5~11.0:1 compression with direct injection with a boost pressure of about 10~11 psi. If you want to take the engine to about 130 lb-ft / liter you need about 18 psi of boost which means your compression (even with DI) needs to go down to about 9.0~9.3:1. That in and of itself is worth about 10% mpg (3~4 mpg) in a small engine in a small car.

Small turbo, high torque, low hp is the worst of both worlds. It has the increased lag and reduced economy of an engine with a larger turbo and about 130 hp/liter, while not having the power and performance.

First off, can you please correct this sentence since it makes no sense at the start of your 2nd paragraph. "What that means is that the power peak arrives at some engine speed lower that."

Second, your first statement would seem to imply that if they have an undersized turbo and over boosted, then you would have early death of the turbo charger. Is that what you are implying?

So then if we go with your line of thought, the performance version at 197hp and 221lb-ft of torque would be a bigger turbo charger, but still undersized and over boosted and this would lead one to think that GM is planning on having these things die by 100,000 miles.

With GM working so hard to change a persons mind, I have a hard time believing they would do this.

The pictures and info on these links is pretty cool. Looks like a nice little engine.

http://gmauthority.com/blog/2012/05/opel-announces-all-new-1-6l-turbo-engine-range/

http://gmauthority.com/blog/2012/08/genera-motors-commences-4-cylinder-powertrain-renewal-with-1-6l-turbo-ecotec/

Exciting is according to this web site, this engine will have dual rails so it can also run CNG!

http://green.autoblog.com/2008/05/15/gm-launches-two-new-turbocharged-engines/

The 197 hp version of the engine should replace the 2.5 in the ATS.

First off, can you please correct this sentence since it makes no sense at the start of your 2nd paragraph. "What that means is that the power peak arrives at some engine speed lower that."

Second, your first statement would seem to imply that if they have an undersized turbo and over boosted, then you would have early death of the turbo charger. Is that what you are implying?

So then if we go with your line of thought, the performance version at 197hp and 221lb-ft of torque would be a bigger turbo charger, but still undersized and over boosted and this would lead one to think that GM is planning on having these things die by 100,000 miles.

With GM working so hard to change a persons mind, I have a hard time believing they would do this.

Actually, that is exactly what I meant. If you any engine is making 206 lb-ft of maximum torque but only 168 hp, the power peak will have to be pretty low in rev range. Horsepower (by definition) = torque x rpm / 5252. If you are making 206 hp at 5252 rpm, you maximum horsepower would be 206 hp @ 5252 rpm. Given that the engine makes "only" 168 hp, it means that torque had fallen off significantly before 5252 rpm. With a flat torque curve -- like most turbo engines have -- 206 lb-ft @ 4300 rpm = 168hp at 4300 rpm. At any rpm above that torque MUST fall off faster than rpm rises otherwise the HP figure will exceed 168hp. At 6000 rpm for instance, torque must have fallen to no more than 147 hp. Otherwise hp will exceed 168 hp.

Now, when I say the turbo is "undersized" I don't mean that it is being overworked and runs ]at damaging speeds shortening it's life. What I meant was simply that the turbo is incapable sustaining maximum boost all the way to the engine's redline. We generally call this an "undersized" setup, whereas a turbo which is capable of sustaining maximum boost beyond the engine's redline or a higher boost than stock is considered "oversized"

This is also the reason why torque on must start falling off from 206 lb-ft no later than 4300 rpm. Because beyond that speed, one of two things (or both) must be happening. Either the turbo is exceeding its maximum rated rpm or it is falling of the compressor's efficiency map, and the ECU must progressive reduce boost above that engine speed so the turbo doesn't become short lived or make more heat than it does pressure which does nothing to get you more power. If this is not the case the engine would continue to make it's maximum torque (which collerates roughly with maximum boost) to a higher rpm and generate a higher hp figure than 168hp.

Personally, I favor designs which have slightly lower torque than hp. This allows lower boost, higher compression which translates to both better fuel efficiency and a more responsive, more linear, engine. Examples of these will be the ATS 2.0T's 270hp / 262 lb-ft (LTG) engine or the Nissan GT-R's 520hp / 451 lb-ft (VR38DETT) engine.

The 197 hp version of the engine should replace the 2.5 in the ATS.

Personally, I'd favor a detuned 2.0L DI turbo for the ATS rated at about 210hp.