This week, I put our long-term test vehicle to work towing a sedan through the Colorado mountains. How did the 2023 Chevy Silverado 1500 with the 3.0-liter Duramax diesel do towing this load? One word: Exceptional.
The 2023 Silverado 1500 has a new interior, small exterior changes and the new LZ0 3.0-liter inline6 Duramax diesel. This diesel replaces the prior LM2 version with improvements in torque, horsepower and better reliability through removing some unnecessary parts.
The towing setup
On this trip, I was towing a 2000 Nissan Altima, weighing around 3,000 pounds, and used a U-haul tow dolly weighing 750 pounds. All told, I had around 650 pounds of payload including the additional 60 pounds tongue weight of the tow dolly and the 320-pound Decked CargoGlide in the bed.
The Silverado 1500 with the Duramax diesel and max towing package is rated to tow 13,000 pounds. It also has a max payload of 1,632 pounds and a Gross Combined Weight Rating (GCWR) of 19,000 pounds. This is my long way of saying, I was well within the towing limits of the truck.
I dropped the tow dolly off in Montrose, Colorado and drove back home the next day not towing.
Overall, the trip is right at 1,000 miles on mostly highways with 17,188 feet of elevation gain and 19,101 feet of elevation loss according to Google maps.
Duramax diesel towing through the mountains
The journey began in Gering, Nebraska, with its 3,911-foot elevation and would take me up and over the Eisenhower tunnel at 11,158 feet as well as over Vail pass, which is 10,662 feet above sea level.
This drive can be sketchy with the spring weather in the Rockies, but I had this week to deliver the car or I was going to have to wait until June. Fortunately, I dodged major weather and only had a slight rain/snow mix around Vail pass.
Starting up the mountains, I saw fuel economy hovering in the low 20s, and by the time I got to Montrose several hours later, the final number was 21.1 MPG. I used about a gallon of diesel exhaust fluid (DEF). No oil or other fluids needed to be added.
It was a fairly comfortable drive, averaging 55-65 MPH. However, the primary issues were a tire vibration from the U-Haul trailer, which caused the steering wheel to shimmy at times, and a problem with the Silverado’s trailer light hookup not recognizing some of the lights. The same thing happened a week earlier when I towed a camper. I’ll have the dealer check that out when I can.
The drive home
Dropping off the car to a very happy daughter, I ditched the trailer and hit the road early to get back home by lunch. This time I could drive faster.
Starting in Montrose, the weather was a bit warmer with low 40s climbing into the mid 50s by midday. Before I got 100 miles down the road, the computer trip showed 31.1 MPG. This is an incredible number since I wasn’t driving for fuel economy and not using an additive. I was literally just driving normally. And for those wondering, I’ve found hand calculating fuel usage to be +/- 1 MPG for GM trucks.
By the time I got to Vail pass, the weather was just cloudy and the rain/snow mix had mostly stopped. Fuel economy hovered around the 27.8 MPG climbing over Vail pass and it climbed back to 28.8 MPG by the time I started climbing up to the Eisenhower tunnel. At the tunnel, traffic was thick with road construction forcing me to slow down to 45 MPH for a stretch, allowing my fuel economy to stay around 28 MPG.
Heading into Denver, I made use of both the exhaust brake and manual shifting with the paddle shifters to hold gears allowing me to rely on the truck to slow me down, not the brakes. This can be critical with brakes getting so hot in the mountains they won’t work correctly after a while.
As I got into Denver, I saw the computer fuel economy jump to 30.1 MPG before heading north to Cheyenne. The drive north was tough with the elevation gain going up to Cheyenne from Denver and then 45+ MPH wind gusts coming from the north-northwest. I thought for sure, I’d see mid 20s for fuel economy by the time I got home.
Crossing the Wyoming/Nebraska state line, I was shocked to see 28.7 MPG on the trip computer, and this got slightly better to 29 MPG by the time I pulled into the driveway with an average speed above 65 MPH for the entire trip.
I ended up using around 2 gallons of DEF, which is about $15 worth. I also only stopped once on the way home for some caffeine and windshield wiper fluid. I didn’t use any oil.
While diesel costs more at the pump right now, the damn impressive fuel economy, the lack of stopping and the time saved not stopping really added up to a great driving experience.
In many gas trucks I’ve owned or tested over the years, I can’t recall one gas full-size truck that would deliver the same results for MPG or lack of stopping for fuel.
Finally, the quiet ride, the smooth power and the most-comfortable seats found in the High Country trim (be forewarned about seat comfort in lower trims), meant I was less fatigued after 16 hours behind the wheel after two days.
The bottom line
This 2023 Chevy Silverado 1500 with the 3.0-liter Duramax diesel isn’t for everyone, and many people still think diesels are loud, stinky and cost thousands more than a gas truck. If fuel economy is at the top of your list as well as smooth, quiet and powerful, then I don’t understand why this truck isn’t at the top of your list. It is literally the best GM truck engine I’ve ever tested in my 12-year career. Period. End of story.