The new 3.0-liter LM2 Duramax diesel engine offered in the light duty Chevrolet Silverado 1500 and GMC Sierra 1500 has been named to Wards Auto‘s 10 Best Engines list for 2020.
Wards drove the 2020 GMC Sierra 1500 Duramax, along with a 2020 Ford F-150 Powerstroke and 2020 Ram 1500 EcoDiesel when deciding on its 10 Best Engines and Propulsion Systems list for 2020. It was most impressed by the GM offering, with editors giving the 3.0-liter LM2 engine points for “its fuel economy and a smoothness debunking diesels’ growly image.”

3.0L LM2 Duramax engine
The publication was particularly impressed with the Duramax 3.0-liter inline-six’s real-world fuel economy. The GMC Sierra with the LM2 engine gets an EPA-certified combined fuel economy rating of 26 mpg and Wards Auto was easily able to match this, achieving at least 24.7 mpg at all points during its testing and as much as 31.9 mpg. It says those numbers “far surpassed,” its observed fuel economy for either the Ford F-150 or the Ram 1500.
“The GM 3.0L is a great daily driver – quiet and calm, a far cry from the heavy-duty diesels that shake your molars loose,” Wards editor Tom Murphy said.
“Hard to find fault with such a smooth-running machine,” added Muprhy’s editorial colleague, Bob Gritzinger. “This, more than any other engine option, seems perfectly suited to a fullsize truck.”
Wards may have been even more impressed with the 3.0-liter Duramax diesel’s fuel economy if they tested it in a 2020 Chevrolet Silverado. The 2020 GMC Sierra 1500 diesel has an EPA certified rating of 30 mpg highway and 23 mpg city for a combined rating of 26 mpg, while the Silverado gets a rating of 33 mpg city and 23 mpg highway for a combined total of 27 mpg. As we reported previously, Sierra models typically come with more content due to their premium status, so they are tested at a higher base weight than the Silverado, giving the Chevy better fuel economy ratings.
With this recognition from Wards Auto, the 3.0-liter LM2 engine with the GM 10-speed automatic transmission has been deemed the best of the new light duty diesel powertrains. We’re sure Ford and Ram will both be hard at work trying to get more fuel economy and smoother running operation out of their smaller diesels between now and when the 2021 model year trucks are released, but for now, it seems GM is the king of the light duty diesel.
Vehicle | Engine | Displacement | Configuration | Horsepower @ RPM | Torque @ RPM | MPG (hwy/city/combined) | MPG vs Sierra (hwy/city/combined) |
---|---|---|---|---|---|---|---|
2020 GMC Sierra 1500 | Duramax Diesel LM2 | 3.0L | DOHC | 277 @ 3750 | 460 @ 1500 | 30/23/26 | -/-/- |
2020 Chevrolet Silverado 1500 | Duramax Diesel LM2 | 3.0L | DOHC | 277 @ 3750 | 460 @ 1500 | 33/23/27 | +3/-/+1 |
2020 Ram 1500 | EcoDiesel | 3.0L | DOHC | 260 @ 3600 | 480 @ 1600 | 32/22/26 | +2/-1/- |
2020 Ford F-150 | Power Stroke Diesel Lion | 3.0L | DOHC | 250 @ 3250 | 440 @ 1750 | 30/22/25 | -/-1/-1 |
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Source: Wards Auto
Comments
Nice
Put it in the Colorado/Canyon
I highly doubt Ford or FCA will be able to beat this engine. The best/ most advanced desiel manufacture engineered this engine for GM..
That inline 6 been around..ever heard of Cummins?
Buddy they can gm isn’t advanced don’t worry your gm product will go down which already is
I think this engine deserves the accolades that it is getting, but Wards also listed the infamous Ford/IH Oh No 6.0 as a ten best engine when it released, so there is that.
I very curious what kind of mileage the 3.0 Dmax would get in the Colorado. If they can pull low 30’s in a full size, I bet it would be in the high 30’s.
The lower FE numbers in the GMC don’t hold up to “higher content” explanation – if that were the case, then gas models would take a similar hit, but don’t. In the GMC, the diesel non-AT4 numbers are the same as the AT4 numbers – and that isn’t plausible when you consider the AT4 economy takes a real hit with the gas engines.
I honestly believe GMC screwed up in reporting the numbers. There’s no reason the diesel in the GMC should get even 1 mpg less than Chevy, especially when gas models take a 0 mpg hit.
GM needs to relook at their calculations. This is bad math or record taking/keeping.
I had a feeling that GM would nail this one out of the park. Ram could upgrade their intercoolers and run some more boost to get a better torque rating, but when you see the real world performance of he two new diesels. The 3.0 duramax delivered zero turbo lag compared to a solid two seconds with the Ram edodiesel. Way to go GM.
I just took delivery of my 2020 Silverado with the 3.0 Duramax. I was tired of the less than stellar fuel economy my 5.3 gas engine delivered. I’m already impressed with the performance of the 3.0. I’ve had the 6.8 and the 1.8 in a Colorado. The 3.0 is going to blow away the 6.8 with miles per gallon and it has pretty impressive torque for a smaller diesel in a 1/2 ton truck.
PLANT THE INLINE 3.0 IN THE COLORADO AND CANYON AND GM WOULD OWN THE MID SIZE TRUCK MARKET.
The RAMS 3.0 diesel is manufactured in Italy which is reason alone that I would never purchase a RAM or Jeep with their diesel option.
My 21 Chevy Silverado RST ZR7 4WD 3.0 Duramax runs smooth and quiet. It rides and performs better than the V-6 Buick 3.8 we traded in on it…