Better than I expected MPGs 6.2L

[tvanort]

When shopping for my next truck, I decided that I wanted to go with the 6.2L because why not! I was a little curious on how big of a difference the mpgs would be, given that everyone's driving habits are different, and you can't believe everything you read online. My first 500 miles were on the highway ranging from 72mph to 77mph. I got an average of 22 mpg. The last 50 miles of my trip I drove 60 mph, and bumped up my mpg to 24! I am definitely impressed! My truck has the max tow package with the 3.42 rear end, so I wasn't hoping for much in the gas mileage department, but I don't think I am that far of from a 5.3 with the 6 speed transmission. Now I am driving in town quite a bit, and my mileage is ranging from 18-20mpg, but I definitely see a huge increase in gas usage when I stomp on it. I can safely say I am smiling the entire time I do though!

['17 Sierra]

You should be the same as a 5.3 during normal driving but when you get on it is when you'll see less MPG.

[amxguy1970]

That is pretty good. You will be about 1 mpg less than a 5.3 given same driver and conditions, ect per what people have tested, GM and magazine tests between the two. My daily drive to the work and gym is no highway and mostly stop lights so I am around 16 mpg average in my 5.3.

 

Tyler

[seamus2154]

The above is inaccurate. I have had 2- 5.3's with 3:42's. 6 speeds('14&'15) and am on my 2nd 6.2 8 speed ('15&'17) all in this new platform. I am the same guy same driver same roads in all 4 vehicles. The 6.2 easily gets better mileage ALL the time. Street and highway. There are several videos on youtube with scientific back to back side by side trucks and the 6.2 wins each time. I could not believe it when I bought my first 6.2. But it will drink if your flooring it. I drive pretty hard but without beating on it and I still always average 21-22 on the highway at 80 and above, flat and smooth here in FLA. Driving nice 70-75 I get 24 mpg. The BIG difference is it does it easily in the 6.2. I had to struggle and baby the 5.3 for better than 20. This is one of those rare times in life that defy logic and what you would figure. Its great engineering. The 6.2 is the bomb. My new truck is a Yukon Denali XL which has to be about 6000 lbs! I am impressed daily with the fuel mileage and am still in awe that it is better than my 5.3's of the past. The performance is too much fun, but thats when it drops to 14-17. Which is still insane, as my old 2001 and 2007 averaged 12-13 all the time!

 

 

 

I get better than these guys do but their 5.3 is an 8 speed which means these are probably 4x4's.

[steve76t]

I have heard that both the 5.3 and 6.2 are very similar in mpg. GMC has both rated at the same 15 city 20 hwy for the 8spd crewcab 4x4s like my new Denali. I've driven about 500 miles with my new truck & have a lifetime average of 18.6 mpg with mixed city & hwy miles. A 120 mile trip last weekend showed a 22.7 mpg average on hilly Northern NV hwys. I have the 5.3L though.

 

Tests I've seen, including the FLT video Seamus posted, show that these two motors do get very similar mileage numbers. The 6.2 makes more power, is faster, and probably a little more fun to play with. However, the 6.2L requires premium 93 octane fuel to perform as advertised and isn't easily found locally. The 5.3 takes regular 87 octane fuel and therefore lower fuel costs. If you tow regularly the 6.2 is probably the way to go. I don't tow anything very often at all so the 5.3L fits my style well.

 

Either way, both are very nice engines that are very good at sipping fuel for V8's.

[SkiDooNick700]

Glad to hear you are enjoying the MPG. I figured I was going to get around 13 or 14 with this but constantly averaging 17 with mostly suburban driving I am happy!

[parthery]

I'm getting between 17-17.5 around town (combination stop and go and freeway).

 

Had it on the road for one extended trip so far and got 21 mpg at 80 MPH.

 

Impressed so far.....

[alrockaz]

The MPG is one of the reasons I got the 6.2. If it was a big decrease vs. the 5.3 I would not have been able to justify the expense. I'm glad to hear of the real world numbers people are getting. I'm just under 17 when doing 100% city driving and I'm usually not easy on the pedal, though I'm not a red light racer either. I haven't had it on the highway long enough to really measure that MPG.

[seamus2154]

I have heard that both the 5.3 and 6.2 are very similar in mpg. GMC has both rated at the same 15 city 20 hwy for the 8spd crewcab 4x4s like my new Denali. I've driven about 500 miles with my new truck & have a lifetime average of 18.6 mpg with mixed city & hwy miles. A 120 mile trip last weekend showed a 22.7 mpg average on hilly Northern NV hwys. I have the 5.3L though.

 

Tests I've seen, including the FLT video Seamus posted, show that these two motors do get very similar mileage numbers. The 6.2 makes more power, is faster, and probably a little more fun to play with. However, the 6.2L requires premium 93 octane fuel to perform as advertised and isn't easily found locally. The 5.3 takes regular 87 octane fuel and therefore lower fuel costs. If you tow regularly the 6.2 is probably the way to go. I don't tow anything very often at all so the 5.3L fits my style well.

 

Either way, both are very nice engines that are very good at sipping fuel for V8's.

 

Very true, I left that part out. It does take premium. I do tow so the 6.2 was a must either way for me, but the enjoyment factor and no lugging of the 6.2 have made me a fanboy. If you did a speadsheet of the 2600 dollars premium for the motor and the fuel price difference over time I am sure I would still do it. This is the strange part. I have a new truck with just 1500 miles. I always run premium and will continue as recommended, BUT.......... We just had hurricane Irma here in Florida and it was so much fun. NOT. Gas was a problem and premium disappeared pretty quickly so I had to fill my empty tank with 87 which was all you could get. After the storm gas was still an issue and 87 was all I could get for 3 tanks in a row. I didn't notice much of a difference and no pinging which the manual said to expect? I floored it and got on it quite a bit and was listening expecting pinging which didn't happen. It still hauled ass. But performance was lower. I had to drive on the highway for 80 miles to family and mileage was the same??!! I was surprised. I am sure if I was towing it would be a big issue but for daily driving I had no issues. I have spoke to a couple of guys who put 87 and 89 in their truck for light daily driving and only 92 for towing. Not me, too expensive of a truck and I am a maintenance nut anyway.

[Limited360]

Very true, I left that part out. It does take premium. I do tow so the 6.2 was a must either way for me, but the enjoyment factor and no lugging of the 6.2 have made me a fanboy. If you did a speadsheet of the 2600 dollars premium for the motor and the fuel price difference over time I am sure I would still do it. This is the strange part. I have a new truck with just 1500 miles. I always run premium and will continue as recommended, BUT.......... We just had hurricane Irma here in Florida and it was so much fun. NOT. Gas was a problem and premium disappeared pretty quickly so I had to fill my empty tank with 87 which was all you could get. After the storm gas was still an issue and 87 was all I could get for 3 tanks in a row. I didn't notice much of a difference and no pinging which the manual said to expect? I floored it and got on it quite a bit and was listening expecting pinging which didn't happen. It still hauled ass. But performance was lower. I had to drive on the highway for 80 miles to family and mileage was the same??!! I was surprised. I am sure if I was towing it would be a big issue but for daily driving I had no issues. I have spoke to a couple of guys who put 87 and 89 in their truck for light daily driving and only 92 for towing. Not me, too expensive of a truck and I am a maintenance nut anyway.

 

The knock detection is rather good on those engines... they will scale the spark advance back based on amount of knock. The difference from a premium and a regular can be managed with the feature... sucks thats all that was available

[RottenDiesel]

I just picked up my new 2018 with 6.2 and took it pretty easy for the first 500 miles. I easily maintained 25 mpg or higher by keeping my speed at 55-60 mph.

 

 

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[Hyogbog]

My new truck uses almost the exact same amount of fuel as my old one. The new truck is around 250lbs heavier since it's crew cab with power seats etc. I use almost a full tank (26 gal) which oddly is the same exact size in both trucks when going from Ottawa to Niagara Falls. The newer 5.3L may be better on fuel then my old one but as I know it's a no brainer especially if you already are in the market for a SLT / LTZ.

 

2011 SLE 5.3L Extended cab 6 1/2 box with 4x4 (3.42 gear ratio)

2017 SLT 6.2L Crew cab 6 1/2 box with 4x4 (3.42's gear ratio)

[JCunningham]

my 2012 6.2l 4wd ext cab (3.42) got the best mpg. Iv had 4 5.3l 2000 (3.73), 2007 3.73), 2012 (3.42) and my current 2017 (3.42) all get less. My 6.2l got 15-20 all my 5.3ls got 13-18mpg all were same 4wd ext cabs

[elcamino]

 

However, the 6.2L requires premium 93 octane fuel to perform as advertised and isn't easily found locally.

Its recommends using premium but does not say you have to use 93 octane. 91 octane is good enough, been using that since my 2012.

 

from owners manual

 

 

If the vehicle has the 6.2L V8 engine (VIN Code J), use premium unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 91 or higher.