28.3 MPG on a recent trip in my 2018 Tahoe RST 6.2L 4x4

[AZRiverRunner]

On a recent solo trip from Vegas to Rancho Cucamonga I got over 28mpg over a 214 mile trip. I snapped the below photo as I was exiting the highway. I had the cruise set to 74mph most of the way, until I got on the Cajon pass, then set to 68 coming down the mountain to allow the engine braking in cruise to slow me. I did not have any traffic the entire trip. At 74mph, the 6.2L motor has so much torque along with the 10 speed trans, it stays in V4 mode except for going up some grades.

If you haven't driven this route, there are a couple passes of around 4,000 ft, so I'd imagine higher mpg would be achievable on a long flat drive.

I do have a Hypertech Energy 2.0 (non-CA version) custom program in the truck, Michelin Defender LTX 285/45R22XL tires @ 45-48 psi and run 91 octane top tier fuel

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Usually, making this trip, or similar trips to and from Arizona/SoCal I get 22-24mpg, but going faster, "with the flow of traffic" of course and with 1-2 passengers and a load of gear.

I had a 2015 Tahoe LT 4x4 5.3L (6 speed trans) and best I got over the 48k miles I owned it was 24.8 on similar trips, averaged about 1-2 mpg less than my 2018 6.2L with the 10 speed trans.

I really love this Tahoe, the 6.2L L86 matched to the 10 speed trans, the Magnetic Suspension, ride/handling, and comfort.

 

[tom3]

In spite of all the reported problems that V4 mode is pretty dramatic in fuel consumption. Pretty awesome outcome on that trip.

 

[AZRiverRunner]

Yes it is, and seems more effective in my 2018, with a lot more torque than in my 2015. In the 2015, V4 mode only engaged rarely at highway speeds.

I find the other vehicle's "auto stop" feature, when the engine shuts off when automatically when you stop, and restarts when you let off the brake, that most other vehicles have is extremely annoying and I keep it deactivated, the thousands of extra start cycles also must create additional wear on the motor.

 

[Brad32486]

I've got a 15 5.3 and, while trying, achieved 29.5mpg over 25 miles. Thought that was pretty impressive, although not usual or realistic for every day

 

[RST Dana]

I've got a 15 5.3 and, while trying, achieved 29.5mpg over 25 miles. Thought that was pretty impressive, although not usual or realistic for every day

I’m guessing you’re believing the display and not actually manually calculating after refueling? That will be your true test.

 

[tom3]

We took a trip down south last week. Three of us and loaded to the roof, driving interstate speeds, 20 mile traffic jam with stop and go, run mid grade BP gas. Actual figured mpg agrees with the readout.

These big machines do pretty good on the highway and I'm always impressed with the power and smoothness of this 5.3 drivetrain. One heck of a fine road machine.

 

[Brad32486]

I’m guessing you’re believing the display and not actually manually calculating after refueling? That will be your true test.

Yeah that is correct, that's why I mentioned 25 mile period. I know there's no way I could get 29.5 over a whole tank. My typical daily driving is shorter trips in town so it would be pretty bad.

 

[MrMonte]

My 2018 Yukon Denali 6.2L 10 speed last 5,700 mile average is 20.5mpg avg speed 37mph. I turned off AFM so no more V4 and installed a 91 performance tune via Flashpaq F5 tuner 200 miles ago and my mileage is 22.1 with avg speed of 34mph.

 

[swathdiver]

Michelin Defender LTX 285/45R22XL tires @ 45-48 psi

That's a lot of air, has it worn down the center of the treads yet?

 

[Jeff_]

That's a lot of air, has it worn down the center of the treads yet?

I was thinking the same thing. Maybe before a long road trip I could see pumping them up to 40psi cold.
But for regular everyday driving, 35psi cold is where I'd like to be.

 

[AZRiverRunner]

That's a lot of air, has it worn down the center of the treads yet?

Nope, They've got over 32k miles on them, only look about half worn, even wear across the treads on all 4 tires. Plus about 5k miles flat towing behind my RV. I've rotated them every 10k miles. The stock Bridgestone tires were worn out at 33k miles, plus about 2k flat tow miles.

 

[AZRiverRunner]

I was thinking the same thing. Maybe before a long road trip I could see pumping them up to 40psi cold.
But for regular everyday driving, 35psi cold is where I'd like to be.

Tire pressure isn't a universal setting for all tires and vehicles. The Tahoe's RST's magnetic suspension rides firm and flat hard in turns, these 22" tires like that pressure with the weight. They grip, corner, and wear perfectly. I had the same tires, except they were a different size, 20" with a taller sidewall on my 2015 Tahoe, I kept them at 38-40, unless I was loaded down and towing my 7,500 boat. That Tahoe road like a couch, but didn't handle corners like my 2018. My point is, on the 2015, it wasn't meant to handle corners like a sports car and tire pressure didn't matter much, other than for load carrying capacity, which is higher with more pressure, up to the tire's max cold pressure.

 

[shekmark]

Wow, I am seeing around 17 mpg average . Very little highway though . I don’t feel like I am leadfooting either.

 

[AZRiverRunner]

That's a lot of air, has it worn down the center of the treads yet?

No, I got over 60k miles on those tires. Could have gone another 10k, but caught the Michelin sale at Costco for a new set.