First Drive: The New 2021 Chevy Tahoe Diesel Hits the MPG Loop With and Without a Trailer!

It's still smooth and quiet as ever!

2021 chevy tahoe diesel
2021 Chevy Tahoe Diesel

How does the new 2021 Chevy Tahoe Diesel perform in the real world? I take it on our highway MPG loop unladen and with a 6,500 lbs trailer to find out if it can really deliver top-notch efficiency. Can it reach the 30 MPG on the highway without the trailer? Here is what happened.

This particular Tahoe is a fully-optioned 4×4 High Country luxury model. It’s equipped with a towing package, and it is rated to tow up to 8,000 lbs. The engine is a 3.0-liter Duramax turbo-diesel I6 with a rating of 277 hp and 460 lb-ft of torque. It’s mated to a 10-speed automatic transmission. It’s basically the same powertrain setup as in the current Chevy Silverado 1500 and GMC Sierra 1500 trucks. This engine has proven to be smooth, quiet, powerful, and efficient in those pickup trucks. It continues the trend in this new Tahoe.

I hooked up our Cimarron Norstar 4-horse trailer from Transwest to the Tahoe. The trailer is weighed done with water ballast to a total weight of 6,500 lbs. This trailer is about 24 feet long and 7.5 feet wide. This trailer side and weight is about what you would be towing if you have a camping trailer or a large boat.

For this highway MPG test, we always use the cruise control system set at 70 MPH with and without a trailer. This is precisely what I did.

With the trailer, the pump showed 12.1 MPG. This is not the highest ever towing efficiency for any diesel truck, but it is the highest for any full-size SUV that we have ever tested! When I ran the same loop without a trailer, the pump returned a result of 27.7 MPG! This is slightly better than the EPA ratings suggest for a Tahoe 4×4 Duramax Diesel. This is also the best result we ever got with a full-size SUV!

The full video of the MPG loop publishes tomorrow on our TFLtruck Youtube channel. In the meantime, here is a complete walk-around of the new diesel Tahoe that we are testing.