I have a 2021 GMC Sierra 1500 AT4 with the 3.0 Diesel engine.
I am getting around 24 mpg on the highway at 75 mph. Power is good, I pull a boat that is around 5400 pounds with ease.
I am well pleased so far with one exception. Several times the truck has failed to start. I press the button to start it, the engine turns over for about 10 second but does not start. It will start the second time almost every try. This has happened about 10 times. I bought the truck in March and it has 19,000 miles on it. GM just released a programming update to resolve this.
When my wife’s Expedition is retired, I am considering a diesel Yukon.
Previous to this truck I drove F250s with diesels.
