Comparing the Cadillac ATS 2L Turbo Torque to the 3.6L V6

[Bruce Nunnally]

Comparing the Cadillac ATS 2L Turbo Torque to the 3.6L V6

Posted on April 22, 2013by bwnunnally

During our recent Cadillac Chat we debated which engine brings the most torque — the highly boosted 2L Turbo 4, or the 3.6L V6?

Here are the engine dyno curves, both for the Cadillac ATS:

This first graph is for the LTG, the 2L Turbo 4. It hits a ‘shelf’ of 260 lb ft of torque at 1700 rpm and holds that level until over 5500 rpm.

The 3.6L VVT DI normally aspirated engine hits a higher max torque at 4800 RPM of 275 lb ft. It appears to slope up from around 240 lb ft to 275 lb feet and back to near 240 lb ft at redline.

After 5500 rpm the 3.6L heads on to peak HP while the Turbo is out of breath, so the V6 clearly has the ‘nod’ at redline. My impression comparing the two charts by sight is that the 3.6L stays ahead all the way through the rpm band — what do you think?

Source: http://caddyinfo.com/wordpress/comparing-the-cadillac-ats-2l-turbo-torque-to-the-3-6l-v6/

[Cadillac Jim]

It looks like the major difference is that the 3.6 liter V6 has an extra 1500 rpm on the top end. In normal driving there isn't much difference, but when horsepower counts the V6 will never drop down to an rpm range where the turbo 2.0 liter will be competitive. But, the lower weight in the front end combined with equivalent performance below 5500 rpm, the 2.0 might be more fun to drive around town.

[Bruce Nunnally]

Here is a layered comparison — the graphs are difficult to compare because they do not have constant x and y axes. I used GIMP to stretch one to align with the other in order to give an apples to apples comparison:

Layered comparison with both engine dyno graphs on the same scale

This makes it harder to read the scales, but what it suggests is that below around 3500 rpm the LTG 2L Turbo makes more torque; after that the 3.6L normally aspirated LFX makes more torque. With an automatic transmission and torque converter, the LFX likely stays above 3500 rpm at open throttle regardless. With variable valve timing, the 3.6L manages a heroic torque curve down low and good power up high.

[Bruce Nunnally]

Finally, as a nod to the V8 fans, here is a comparison between the two Northstar FWD variants, overlayed together, against the 3.6L RWD VVT V6.

What this shows is a) this is a messy way to discuss and the 4.6L Northstar in either variant pulls more torque, earlier, and holds an advantage until past 6K RPM when the smaller 3.6L V6 finally wins only at peak hp.

[Bruce Nunnally]

As a note, the Northstar graphs were not done to the same J1349 standard, which can effect the graphs slightly.

[Bruce Nunnally]

It looks like the major difference is that the 3.6 liter V6 has an extra 1500 rpm on the top end. In normal driving there isn't much difference, but when horsepower counts the V6 will never drop down to an rpm range where the turbo 2.0 liter will be competitive. But, the lower weight in the front end combined with equivalent performance below 5500 rpm, the 2.0 might be more fun to drive around town.

Yes. It is interesting that that 2L turbo has uniformly tested as about 0.5-1 sec less quick than the 3.6L ATS. I think it suffers from gearing and rev range -- it needs 2 shifts to reach 60 mph. That means in real life it will 'drive' quicker than it tests.

[cdgrinci]

While the turbo has good torque, there is just that little lag from just off idle to 1700 rpms; the 3.6 produces torque starting at 1000 rpms. Spirited driving and it would be almost even-steven (for the most part; variances again at the top of the performance rpm) but around town and typical highway, nod to the V-6.

[stroker49]

With 8,30 usd/gallon gas it is an easy choice here in Europe!

The same GM High Feature V6 engine in a 2,8 l version was used in the latest Saab 9-5. It had 300 ft-lb from 2000 rpm.

Normally aspirated engines sucks!

[Cadillac Jim]

I think we have seen the future, and the future is coming through an intercooler.

[Dasher]

When I first read this post didn't read far enough to see your comparison of the two Northstars. I owned

a couple of STS's but never an SLS; but I drove a couple and I always felt they were geared differently

and the SLS seemed to have more go in the lower ranges while the STS had more on the high end

and I mentally made this comparison between the V6 and the 2 L Turbo when I bought my ATS Premium

a month ago and it was the deciding factor when I picked the 2 L Turbo. I have an aversion to those

high speed tickets and I picked the 2 L because I thought it was more fun at the lower speeds.