Originally designed to propel SUVs and pickup trucks, GM’s 4.5-liter Duramax V8 turbodiesel powerplant could find its way under the hood of the Cadillac CTS. The idea is unusual, but perhaps not a controversial as the prospect of a four-cylinder Caddy. If a new report is to believed, GM is strongly considering the possibility.
The Duramax mill delivers 310 horsepower, and, as diesels do, a massive amount of torque — 520 pound-feet to be exact. Critically, GM says the engine meets emissions standards in all 50 states.
The engine might serve to fill the gap between the 304 horsepower V6 and 556 horsepower “V” in the CTS range, according to Motor Trend, but we think it would have to be up-tuned to around 420 horsepower to accomplish that goal.
While shoehorning a diesel into a Cadillac is a bit of a risk from a marketing point of view, the technical feasibility of such a move is very favorable, and the cost to GM would be minimal. The CTS is already capable of fitting the engine without issue, and a suitable transmission is readily available.
Frankly, we’d rather see a twin-turbo V6 with over 400 horsepower added to the CTS lineup, but the Duramax option might be more viable to a cash-strapped GM.



10/15, 1:06 PM
posted by:
pavlindrom
I think diesel is great. I don’t see a problem with it.
10/15, 1:31 PM
posted by:
Fromes
Humm, it would make more sense to me to offer the 2.7L turbo diesal they sell in europe in the CTS here in the states, I just think the Duramax might be seen has a tad crude for a CTS, though, I would love to see that engine in an Escalade
10/15, 1:35 PM
posted by:
johnnycanuck
Spend what few dollars you have elsewhere GM. This thing would rot on the lot before you’d get rid of it. Your customer demographic may be very different from what it was only a few short years ago, but they’re still not ready.
10/15, 1:35 PM
posted by:
writeeddie
I wondered if the Duramax is smooth enough for a “car” or is it going to make the CTS ride like a trampoline? I thought the whole idea of putting a diesel is for the MPG. Why don’t they bring some of that Euro-spec V6 Diesel instead? Like the writer was saying, most true performance chasers likely with stick with Twin Turbo Gas V6.
10/15, 1:45 PM
posted by:
Lariat Luxury Locomotive Liner No.3
GM is milking the CTS lineup to death—literally. Atlas shrugged.
10/15, 1:46 PM
posted by:
JoshyLofty
do it.
10/15, 4:10 PM
posted by:
oldraven
I think this is a great idea, and will probably help Cadillac come closer to CAFE, if the engine is tuned for economy and not pulling stumps, as it would be for their full size trucks.
10/15, 4:11 PM
posted by:
oldraven
I do think using the V8 might be overdoing it, but at the very least a V6 turbo-diesel would be an ideal middle range CTS, and would probably make the car an even bigger hit in Europe.
10/15, 4:56 PM
posted by:
golf4me
Just imagine a car the has over 500lb-ft of torque and gets probably close to 30-32mpg…that would be nice. Put it in the wagon, and I will sign the dotted line, GM.
10/15, 5:04 PM
posted by:
bcjohnso99
People, this is NOT the Duramax from the trucks. This is a totally new engine with a VERY high level of refinement. It has only been tested in pre-production form but the results are impressive.
As for the 2.9l turbo, I think it would be a better choice but I don’t believe it is 50 state legal.
10/15, 5:10 PM
posted by:
bigp
thats to much in the added weight ttv-6
10/15, 8:22 PM
posted by:
aexcorp
Diesel is a great idea, and if they can tune it to ~400 horses, it will be quite a nice performance car, without rivaling with the V since the weight bias will make it much less exciting on the track (diesel blocks are heavy due to compression ratio). However, I really think we need to see the price of diesel fuel drop a little to make this really competitive. I still don’t get why it’s so expensive states-side…
10/15, 8:28 PM
posted by:
1c3d0g
EGGcellent!
Finally, GM is listening…these are exciting times!
10/15, 8:55 PM
posted by:
desertdriver
Mmmmmmmm……torque
10/15, 9:31 PM
posted by:
angelo
Let’s now see what the MPG numbers would be…
10/15, 9:43 PM
posted by:
oldraven
Diesel blocks are heavy….. because they’re usually made of iron.
And this IS the Duramax from the trucks. The engine was made specifically as a smaller option to the large Duramax. It has always been a truck engine, and it has yet to be tested in a car. The story here is about taking the NEW light duty Truck Duramax and using it in a Cadillac. The 4.5 is a truck motor, refined or not.
10/16, 12:21 AM
posted by:
RotaxKart
Build it! Just put a rearend strong enough to hold the torque…. I blew ONE rear in a V and GM denied my ass to fix it under warranty.
10/16, 7:00 AM
posted by:
tob
I like the idea but there is not enough room under the hood for that engine. Maybe the could put a high rise cowl induction hood to make room and then put french doors on it so you can see the intake through the hood.
10/16, 7:20 AM
posted by:
sudo95
Old Raven is definetly past his prime considering he’s talking about old diesels. This motor is lighter than a gas V8 w/out the turbo on it. All the Euro super sedans have a hi-po diesel option and with over 500 ft-lbs this thing will fly. Remember, it is torque that turns the wheels.
10/16, 3:12 PM
posted by:
Z06ified
oldraven – who cares if it’s a “truck motor”? Lots of engines in cars are also in trucks. The Supra Turbo engine was made from a truck motor. Many other great car engines were also used in trucks. Doesn’t matter. A great engine is a great engine – doesn’t matter what it is used in.
02/26, 9:55 AM
posted by:
Other Man
Hopefully it’s got the buttery refinement of the V-8 diesels you see in overseas Benz and Audi models.
Hope it’s still a go. A twin-turbo V-6 with 370+ hp would be quite respectable as well.