5.3 v 6.2 daily use and mpg

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

SAdude

Full Access Member
Joined
Oct 28, 2020
Posts
181
Reaction score
158
The 6.2 requires premium gas and actually tows less than the 5.3. The 5.3 is not sluggish in any way. I don't think I could justify the 6.2 just for a faster 1/4 mile time...these are full size SUVs not sports cars.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
30,773
Reaction score
48,479
Location
Stockton, Ca.
The 6.2 requires premium gas and actually tows less than the 5.3. The 5.3 is not sluggish in any way. I don't think I could justify the 6.2 just for a faster 1/4 mile time...these are full size SUVs not sports cars.
LOL, I drive mine like a dam sports car, the 6.2 stomps all over the 5.3 obviously you have never compared the 2 to each other.

to the OP go test drive a 5.3l and give it a workout, then go test drive a 6.2 doing the same. then make your decision. the gas mileage factor is nill
 

mikeyss

Full Access Member
Joined
Nov 11, 2011
Posts
1,758
Reaction score
3,393
Location
Longmont, Colorado.
LOL, I drive mine like a dam sports car, the 6.2 stomps all over the 5.3 obviously you have never compared the 2 to each other.

to the OP go test drive a 5.3l and give it a workout, then go test drive a 6.2 doing the same. then make your decision. the gas mileage factor is nill

Agreed, I had a 5.3 Tahoe and now have a 6.2 Tahoe... Gas mileage is like 1mpg different in the city, no real difference on the highway. The 5.3 IS a good, adequate engine... But it sucks in comparison to a 6.2 no matter how you look at it. For someone that only drives 5 miles to the grocery store, or taking the family to church, the 5.3 is perfect. The 6.2 is better suited for the heavy weight of the vehicle and makes towing a breeze.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
30,773
Reaction score
48,479
Location
Stockton, Ca.
The 6.2 requires premium gas and actually tows less than the 5.3. The 5.3 is not sluggish in any way. I don't think I could justify the 6.2 just for a faster 1/4 mile time...these are full size SUVs not sports cars.
Also the tow rating has nothing to do with the engine size, the the tow rating is based on the gear ratio commonly used in the 5.3 vs the 6.2 there are 6.2's out there with the same gear ratio and therefore have the same tow rating and if that is really a deciding factor the gear ratio can be changed if so desired.
 

Drwinlied

Full Access Member
Joined
Nov 21, 2020
Posts
183
Reaction score
261
Ding ding ding. Engine size is not THE determining factor for towing at all. I'm sure you can spec and order a 5.3 equipped vehicle to out-tow a standard equipped 6.2, but "the 6.2 tows less than the 5.3" is all sorts of bad info.

Generally speaking, the bigger the engine, the better the odds it has better hardware to tow heavier loads; research would be required to confirm. Either way, NEVER trust what the salesman tells you what you can tow and there is a LOT of fine print for GM claims as well...it's a hell of a lot more than what engine is in there...

Back on topic:

I've also owned both a 6.2 and a 5.3...get the 6.2. Neither is a prius and they are close enough in mpg that the benefits of the 6.2 far outweigh the experience of the 5.3. But as others have said, if this is a soccer mom type hauler, the 5.3 will be fine. But if I had the scratch to where I was cross-shopping them; 6.2.
 

Tonyv__

Full Access Member
Joined
Apr 18, 2018
Posts
4,644
Reaction score
10,894
Location
Bucks county PA
LOL, I drive mine like a dam sports car, the 6.2 stomps all over the 5.3 obviously you have never compared the 2 to each other.

to the OP go test drive a 5.3l and give it a workout, then go test drive a 6.2 doing the same. then make your decision. the gas mileage factor is nill

my first 6.2. And I definitely drive it like a sorts car lol
 

SAdude

Full Access Member
Joined
Oct 28, 2020
Posts
181
Reaction score
158
Ding ding ding. Engine size is not THE determining factor for towing at all. I'm sure you can spec and order a 5.3 equipped vehicle to out-tow a standard equipped 6.2, but "the 6.2 tows less than the 5.3" is all sorts of bad info.

Generally speaking, the bigger the engine, the better the odds it has better hardware to tow heavier loads; research would be required to confirm. Either way, NEVER trust what the salesman tells you what you can tow and there is a LOT of fine print for GM claims as well...it's a hell of a lot more than what engine is in there...

Back on topic:

I've also owned both a 6.2 and a 5.3...get the 6.2. Neither is a prius and they are close enough in mpg that the benefits of the 6.2 far outweigh the experience of the 5.3. But as others have said, if this is a soccer mom type hauler, the 5.3 will be fine. But if I had the scratch to where I was cross-shopping them; 6.2.

It's not bad info, it's fact that 6.2 max tow is 8300 vs 8400 for the 5.3.... Considering same gear ratio which is standard across the board on 21s.

Also I agree that MPG is similar, but cost of fuel is not... Premium vs regular. So if the OP is concerned with cost of ownership then that is a factor worth considering.
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
21,324
Reaction score
30,320
Location
Treasure Coast, Florida
It's not bad info, it's fact that 6.2 max tow is 8300 vs 8400 for the 5.3.... Considering same gear ratio which is standard across the board on 21s.

Also I agree that MPG is similar, but cost of fuel is not... Premium vs regular. So if the OP is concerned with cost of ownership then that is a factor worth considering.

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.
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
21,324
Reaction score
30,320
Location
Treasure Coast, Florida
upload_2020-11-22_12-18-49.png
 

SAdude

Full Access Member
Joined
Oct 28, 2020
Posts
181
Reaction score
158
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

Full Access Member
Joined
Jan 22, 2019
Posts
330
Reaction score
312
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

TYF Newbie
Joined
Nov 7, 2020
Posts
16
Reaction score
28
Location
Spokane, WA
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

Member
Joined
Jul 31, 2016
Posts
79
Reaction score
56
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

Full Access Member
Joined
Jul 20, 2020
Posts
2,284
Reaction score
2,774
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...
 
Joined
Dec 1, 2020
Posts
33
Reaction score
32
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

Full Access Member
Joined
Aug 21, 2020
Posts
448
Reaction score
418
Location
Michigan
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.
 
Last edited:

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,849
Reaction score
20,430
Location
Richmond, VA
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

Full Access Member
Joined
Jan 16, 2021
Posts
224
Reaction score
136
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.

Screenshot_20210323-194559.png
 

killjoy

TYF Newbie
Joined
Aug 2, 2011
Posts
20
Reaction score
12
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.
 
Last edited:

Forum statistics

Threads
138,119
Posts
1,999,632
Members
103,046
Latest member
varminpoolteam

Latest posts

Back
Top