We recently spent a week driving the 2020 Chevrolet Silverado 1500 Duramax – the one powered by the turbo-diesel 3.0L LM2 I-6 turbo-diesel Duramax engine. Much like all-new GM T1 platform that underpins the new Silverado, the straight-six diesel motor is also all-new, rated at 277 horsepower and 460 pound-feet of torque while being mated to the GM 10-speed automatic transmission that sends either to the two rear wheels or to all four.
Many of you chimed in with questions about the truck, and we’re here to provide you the answers. Here we go.
Q: I have heard of overheating issues. Is this true? Are you having overheating issues?
A: A similar question was asked to us when we drove the 2020 GMC Sierra Duramax. Much like we said for the Sierra, we experienced no temperature-related issues while driving the Silverado. In addition, the engine also performed very much like a gasoline unit during cold starts, with the temperature gauge rising to optimal levels after only a short time driving. In other words, nothing alarming was observed. However, we should note that we didn’t perform any towing during this particular test.
Q: Is there an electric version?
A: Not yet. As we write this, there are no mass-production electric pickup trucks on the market, though several carmakers like Tesla, Rivian, Ford and GM have announced plans to bring such a product to market. In fact, General Motors was supposed reveal the much-anticipated GMC Hummer EV in May 2020, but the event was postponed due to the COVID-19 global pandemic.
Besides the GMC Hummer EV, we have also heard whispers of an all-electric Silverado in the works and we expect such a model to become available in the next few years.
Q: How is the NVH of the Duramax engine? How well does it accelerate off the line?
A: Consider us impressed by this new Duramax inline six. Thus far, we have drive it in two different applications – the Silverado High Country being discussed here, and the GMC Sierra Elevation. In both cases, we were very surprised by how quiet and smooth this diesel engine is compared to the competition.
As a matter of fact, we also recently drove the 2020 Ram 1500 EcoDiesel. We not only found the Duramax to be generally more refined than the Ram’s turbo-diesel V6, but a livelier motor, too. Throttle response is considerably better in the Chevrolet Silverado and the engine revs a full 1,000 rpm higher, allowing it to feel more energetic and eager. Off-the-line acceleration is more than ample, mostly due to the fact that the engine produces its 460 pound-feet of torque at just 1,500 rpm.
Q: How does it compare to the 6.2L? Pulling, passing, overall driving?
A: Although the Duramax’s maximum torque rating of 460 pound-feet is identical to that of the available gasoline 6.2L L87 V8, its power delivery isn’t quite as linear as its gasoline counterpart. That said, we weren’t disappointed by the engine’s grunt. Acceleration is brisk, better than the 5.3L L84 V8 due to the fact that torque is available almost immediately, lower on in the rev range. But the Duramax engine still can’t match the smoothness, linearity and high-rpm performance of the 6.2L.
Q: Can you turn off the start/stop feature?
A: Yes. We know that engine auto stop/start has been a source of many complaints from owners of various GM vehicles, and although it hasn’t yet been applied to Chevrolet’s entire lineup, we’re happy to report that yes, one can indeed turn it off in the 2020 Chevrolet Silverado. This is the case for all models and trim levels.
Q: I also want to know about real-world performance, mileage and how that 10-speed transmission works.
A: We performed a similar fuel economy test on the Silverado as when we drove the Sierra Duramax and recorded similar readings. EPA-estimated ratings for the 2020 Chevrolet Silverado Duramax are 29 mpg highway and 23 mpg city. These are actually better numbers than its mechanical twin, the GMC Sierra Duramax, which advertises 22 mpg city and 26 highway. The discrepancy between the two is explained in this GM Authority exclusive.
During our drive with the Silverado, we easily recorded 20 mpg in the city and 25 on the highway, numbers that are considerably better than delivered by the available V8 engines.
As for the ten-speed automatic gearbox, we have absolutely nothing negative to say. In every vehicle we’ve driven with the new transmission thus far, the gearbox has done a formidable job maximizing the engine’s powerband, shifting smoothly and never hesitating to downshift when asked.