5.3 vs 2.7

repairman54 · October 31, 2023

My 6.2 gets 20 mpg easily and consistently. Old '11 Tahoe 5.3 at its best barely made 19 on identical roads and trips, usually only 18 mpg.

Not loaded up figures also. And no comparison to the power on tap with the 6.2.

Look at the window stickers, same mpg ratings for the 5.3 or the 6.2.

KARNUT · October 31, 2023

My 02 5.3 avalanche with the 373 gear got 17 mpg at 72 mph on the interstate. My 14 gmc with the 342 gear got 22 mph at 72 mph. I posted it at the time on an old gas mileage thread on this forum. With several hundred miles driven on that tank. I saw as much as much as 24 mpg at 60mph. Those were normal for that truck.

Edited October 31, 2023 by KARNUT

TrueBlue · November 3, 2023

In June I bought an LT with the 2.7. I liked the grunt it put out. But at 700 miles the oil pan started leaking, and it gave me a chance to rectify my "mistake" of not getting the 5.3 to begin with. I also was just not satisfied with the sound of the motor. So I traded it back in to the same dealer. Cost me a little more to get into the 5.3 that way, but I'm completely happy with my truck now.

I've had five brand new Chevy trucks in my life, along with a few used ones and I have to say that I like this one the best. So long as it treats me well for as long as the others did I will have no regrets. I put a Magnaflow 14" on it and it now sounds as it should, imo. I drive around in L9 all the time to keep it running all 8, and it has as much grunt as I need. A bit less than the 2.7 but that's due to the turbo on the latter. And I like the 10sp better than the 8, even though I'm only using 9 of the gears. I've had a couple of 350's in my trucks, and a 400 small block. None of them put out 355hp or close to 400lbs ft of torque. Technology has made for some great vehicles in the last 25 years or so. I average close to 18mpg every tank. The 5.3 is a hoot.

Edited November 3, 2023 by TrueBlue

Vincej138 · November 7, 2023

Ive had my 2.7 HO for about 5K miles. For the first 4000 it was stock. The motor has 100% surpassed every expectation I had on it. Pulling hills with the turbo you fly past other trucks while getting 20+mpg. The power is there and the torque is there. The very top end it gets sluggish, but you rarely drive there. Its quiet if thats what you like, and the light overall weight rides nice and helps with wear and tear.

The last 1K miles ive since added a 3" lift and 35's with a black widow muffler and have a CAI and hot/cold pipes in the garage to still get put on. Yes the MPG has gone down as expected but i'm still about 17mpg city with all that low end pep and it can still break the 35's loose. It doesn't sound like a honda with the black widow (they love turbo's) Just a muffle delete it likely would though.

If I had to do it all over again, I would stay with the 2.7L

SILVER SLED · November 13, 2023

My ‘21 6.2 and my previous ‘18 6.2 got better gas mileage than my ‘15 5.3. All were ccsb 4x4.

Gangly · November 27, 2023

I have 115k+ miles on my 2020 5.3 and there is no lag whatsoever. It gets after it whenever I need it to.

Mshawn · November 30, 2023

On 10/29/2023 at 2:23 PM, Silverado4x4 said:

I don't know what year your Ram was but all new vehicles come with torque management to protect the drivetrain. When my 5.3 was new it learns your driving style with the tranny but after I put about 1000 miles on or give our take it really woke up power and shifting wise, I love my 5.3 power and more than enough for what I need. Iam with you on the 4 cylinder motor as I don't want a 4 cylinder in a truck I don't care if it had 500hp but its always revving rpms and can't get past the sound of it. I could hear it now from people " Hey man nice truck what motor you have ummm its a 4cylinder" WHAT? But iam not downing it but it's not for me. Thats why there are choices.

The 2.7turbo is a great motor, however I buy the 5.3. I love it. The more I drive it the more responsive it gets. A lot of the lag is due to fuel management and driveline protection ,But it learns as you drive it. You will always have a little bit of lag in the new trucks. Doing a dfm delete helps a lot. I notice when I drive mine more aggressively that the next time I get in to go somewhere it is very responsive and aggressive for a little bit while I’m driving normal. Can’t go wrong with either engine though. The 2.7 turbo is a beast , well built engine in my opinion.

Mshawn · November 30, 2023

On 10/30/2023 at 6:19 AM, dieselfan1 said:

10 mpg from a 6.2????

C'mon man this is 2023 not 1983

My 2023 High Country 6.2 has averaged 18-19 mpg since day one.

My best was a 100 mile run averaging 24 mpg.

I also have a 2022 with the 5.3

and it doesn't get as good mpg

Average of 16-17 mpg since it was new.

Work and back is 80+ miles for me and I’m getting 22-23 consistently with my 5.3 and I’m a crew cab z71 5.3 L84 all interstate though.

Silverado4x4 · November 30, 2023

7 hours ago, Mshawn said:

Work and back is 80+ miles for me and I’m getting 22-23 consistently with my 5.3 and I’m a crew cab z71 5.3 L84 all interstate though.

Iam getting the same mileage as you on the interstate but I did see 27mpg on a 50 mile average on the dash.

lowrider · November 30, 2023

I'm surprised no one has mentioned "Sport Mode". I use it all the time. I feel no lag with my 5.3

Lou

Edited November 30, 2023 by lowrider

Mshawn · December 1, 2023

11 hours ago, lowrider said:

I'm surprised no one has mentioned "Sport Mode". I use it all the time. I feel no lag with my 5.3

Lou

I’ve noticed that too. In sport mode it’s a lot more responsive. Thanks for bringing that up

ember1205 · December 1, 2023

4 hours ago, Mshawn said:

I’ve noticed that too. In sport mode it’s a lot more responsive. Thanks for bringing that up

Granted, I've barely made it past 500 miles on the new truck and I do know that the various control modules will take some time to adjust, but I notice NOTHING different from Sport Mode on my truck.

GMC Guy77 · December 6, 2023

On 10/29/2023 at 11:29 PM, newdude said:

Do you drive with your foot stuck to the floor? Or idle a lot? Stop and go? Because a 6.2 will get way more than 10 mpg any day of the week otherwise. We have a 2020 Tahoe with a 6.2/10 speed in our loaner fleet and in 7,000mi its averaged 19.5mpg.

5.3 with the 10 speed is a great drive. 5.3 is cheap to operate too because it just needs 87 octane. 10 speed fires off shifts and allows that 5.3 to work its power better than the 6 and 8 speeds it had before.

2.7 Turbomax is a great driver as well, especially over the 19-22 non HO/Turbomax ones. And it too just needs 87 octane. I have a 2.7 HO and absolutely love it. More than both 5.3/6 speed trucks I had, a 2018 and a 2012.

6.2 is a blast but 91 octane or higher is a must and that can add up if you are on a budget.

I thought it was recommended to use at least 91 octane in the 2.7 turbos, using 87 will affect mpg's and engine wear and tear long term.

newdude · December 6, 2023

18 minutes ago, Chris Barber said:

I thought it was recommended to use at least 91 octane in the 2.7 turbos, using 87 will affect mpg's and engine wear and tear long term.

87 is all that's needed. GM engineered and tuned it for 87.

ember1205 · December 6, 2023

20 minutes ago, Chris Barber said:

I thought it was recommended to use at least 91 octane in the 2.7 turbos, using 87 will affect mpg's and engine wear and tear long term.

Nope. This is from the 2024 manual, but same Turbomax engine.