5.3 v 6.2 daily use and mpg

[SAdude]

In the first few years of the GMT900 wagons, the tow ratings were inconsistent too. The Denalis were rated to tow less than later years at first and there were no changes mechanically between them. Might have been that they just weren't sure enough of their product yet. One of the new T1 pickup truck options picked up an extra few thousand pounds towing capacity recently because the engineers said it had excess cooling capacity to handle the extra weight. I think it was one of the diesels.

The max tow wieght differences are negligible anyways when within a few hundred lbs. The main advantage the 5.3 has over the 6.2 high country is lower curb weight and therefore higher max payload. The limiting factors in towing with a SUV are payload and tongue weight and the 5.3 has more capacity in both. I looked at several door jamb stickers on dealer lots and the tahoe/yukon thats most capable of heavy towing is the 2WD 5.3.

 

[mb1500]

The max tow wieght differences are negligible anyways when within a few hundred lbs. The main advantage the 5.3 has over the 6.2 high country is lower curb weight and therefore higher max payload. The limiting factors in towing with a SUV are payload and tongue weight and the 5.3 has more capacity in both. I looked at several door jamb stickers on dealer lots and the tahoe/yukon thats most capable of heavy towing is the 2WD 5.3.

Same with just about any half ton on the market, especially the loaded ones.

 

[Norm 427]

I just returned from a 2500 mile road trip (with a small amount of in-town driving) and got 19.92 mpg with the 2021 SLT 5.3. I first put the odo up against my garmin gps and found the Yukon odometer to be essentially dead accurate. Then I kept track of the gallons consumed. Speed was about 3 mph over speed limit. The dash MPG is about 0.3 optimistic. Overall, I'm pleased.

P.S. The first 500 miles was with stiff headwinds. I'm confident I could have had 20+ mpg without those winds.

 

[Campingfamco]

My Denali with 700 miles on it guzzles gas like it’s going out of style! I’m getting 13-14. Mainly because I’m always waiting for my wife ot come out of the store, so I’m idling a lot. Can’t wait to take a road trip to see how it does. One thing I’m worried about is the 24 gallon fuel tank. I wish it was bigger. When I seem like I’m on empty it only takes 18 gallons.

 

[Stbentoak]

My Denali with 700 miles on it guzzles gas like it’s going out of style! I’m getting 13-14. Mainly because I’m always waiting for my wife ot come out of the store, so I’m idling a lot. Can’t wait to take a road trip to see how it does. One thing I’m worried about is the 24 gallon fuel tank. I wish it was bigger. When I seem like I’m on empty it only takes 18 gallons.

This sounds a little more like reality. That small tank bothers me too, I think it should be 30 gal on a vehicle this size.
Also a reason why we are going Duramax...to get some range out of that tank and not have to stop frequently for fuel...

 

[Northern Mi Rich]

Just another data dump - just completed a 1300 mi round trip Traverse City to Minneapolis. Drove 85% highway, also hit snowstorm where I was traveling 20 mph in 4WD for 100 miles on I-94. Bottom line showed 19.6 mpg with the 2021 SLT 5.3 engine. Total vehicle mileage is now 2100 miles.

 

[Fireman591]

I just returned from a 2500 mile road trip (with a small amount of in-town driving) and got 19.92 mpg with the 2021 SLT 5.3. I first put the odo up against my garmin gps and found the Yukon odometer to be essentially dead accurate. Then I kept track of the gallons consumed. Speed was about 3 mph over speed limit. The dash MPG is about 0.3 optimistic. Overall, I'm pleased.

P.S. The first 500 miles was with stiff headwinds. I'm confident I could have had 20+ mpg without those winds.

Wind is a big factor from what I could see with the 5.3. Going into a head wind I was getting 17 mpg going with that same wind a few minutes later I was around 23 mpg. I was doing 70 mph and the wind was a steady 20 mph.

 

[Geotrash]

One thing not mentioned so far (unless I missed it), is resale value. The 6.2 will net more down the road. Like others here, I've owned both 5.3 and 6.2 variants and I'm never going back to the 5.3.

 

[Gibby13]

While they do recommend premium(93) gas for the 6.2 it is not required. As low as 87 can be used as long as their is no knocking.

In our '11 Escalade we never used premium and had around 120k on it when we traded it in and never had a single issue with the engine. We averaged around 17mpg.

We've been using regular in our '21 Denali so far and only averaging 12.5mpg after 1400 miles. Told the wife the other day next time to go premium for the next 1400 miles and see how it goes.

 

[killjoy]

My advice to the OP is to decide if the 6.2L is worth $10k (+15% MSRP) more than the 5.3L, not to mention the need to fill up on Premium vs. Regular. I also am not a huge fan of all of the chrome bling on the Denali (YMMV), and would much rather have the AT4 look.. which the 6.2L isn't available on. I also live in a state that has shit roads, and while I like the look of the Denali's 22" rims, I don't like road feel or cracked rim replacement cost.

Yes, I have driven GM trucks with the 6.2L. Yes, it has some more power/balls. That said, your 6.2L Denali is not going to be out drag racing a Ford Raptor or TRX. 5.3L is 355h/383t, 15.5s 1/4 mile. 6.2L is 420/460, 14.5s 1/4 mile. Either is far cry from the TRX/Raptor's ~700hp and 12.x second 1/4 mile times. The reality is the 5.3L is more than enough to do just about anything you'd ask of the truck, it's about $10k cheaper to buy all in, and op cost is lower due to fuel efficiency and ability to use regular gas. I'd love a 6.2L in my AT4, but it's not available, and even if it was, might be hard to cost justify IMO depending on the $ delta. If GM kicked the 6.2L performance up into the 500hp+ range, or to compete with the TRX, would be a whole 'nother discussion. As it sits today, the 6.2L is just a "slightly less slow than the 5.3L" option.