6.2 Gas Milage.....

Wires · October 1, 2011

I'll be happy if mine gets what my '98 5.7 did.

And after nearly four months of ownership, and 5,000 miles, it does. 14-15 avg. city, 18-19 avg highway. All with 4 times the power of my '98 5.7 so I am extremely happy.

Thats what I'm getting on my 08 6.2l. No complaints at all. Especially when you pull out to pass someone on the 2-lane blacktop, lay into it, and it rapdily rockets you to unsafe road speeds.

blairlee · November 9, 2011

After pretty consistenly getting 14.5ish mpg, my last two fill-ups have yielded around 15.5 mpg. Not sure where the bump is coming from; maybe the a/c is sucking less power because of the cooler weather.

The other day, I was experimenting with highway speeds and mpg. I seem to get the best mpg at 60 mph, not 65 mph as I'd originally thought. Can't complain that the engine loafs along at 1500 rpm at those speeds.

2010LTZ4x4 · November 10, 2011

the best way to get good gas mileage is to leave my truck in the garage.

tyhuck · November 10, 2011

So, is 93 suggested for the 6.2 or are you guys just running it just because you can?

blairlee · November 10, 2011

It's suggested, and you end up getting better fuel efficiency because the engine isn't pulling timing from knock.

ambro_52 · December 13, 2011

Just made a 400+ mile round trip from the northwest corner of illinois to Bloomington IL. Ran a tank of 87 octane down and got 13.3 mpg. I was on empty and filled up with the Shell Premium which was 92 octane for the trip home. The tank was completely empty (think i put 24 gallons in) and on the way back i got 13.8 mpg. I also switched back to my factory rims which are dressed in 285 Cooper STT's. Needless to say i was a bit disappointed in the fuel milage. I ran about 71 mph all the way down and about 68 mph on the way back. Earlier this summer i took a trip up to Wisconsin on a tank of fuel and i was getting right at 17 mpg with my 20's on but i was running top speed of 60. I was super impressed with that so thats why i'm a bit disappointed with my trip to the south.

Daryl Z71 · December 13, 2011

I've had mine since the day before Thanksgiving, and I'm Averaging 14.7 MPG

ajensen383 · December 13, 2011

The last 2 days I put about 400+ miles on my NHT truck.. It was a mix of backroads and highway.. On the highway I was running about 70-75 or so and my average is right around 16.5... Now back and forth to work, (6miles each way) I can keep it around 15 or so... Now my best run on the highway was going south babying it at around 60 for over 100 miles and netted 21mpg. according to DIC.... When I drive normally (about 65 ) on the highway I routinely get about 18-19MPG...

I also found out that 89 octane works just as good as 93, I dont see much difference in power or economy.. It doesnt like 87 at all and it shows in power and economy, but it seems to do well on 89.

Brock Samson · May 31, 2012

I hate to bump this thread out of the past, but I'm curious what type of mileage I could expect for highway at around 75 MPH? I see some decent highway numbers mentioned, but without a relation to speed, those don't seem to help much.

ChevyTech77 · May 31, 2012

I hate to bump this thread out of the past, but I'm curious what type of mileage I could expect for highway at around 75 MPH? I see some decent highway numbers mentioned, but without a relation to speed, those don't seem to help much.

Does this help?

Coolmaker · May 31, 2012

My 2012 2 wd 6.2 gets about 16.5 for me around here (mostly rural open road), even pulling a trailer with a 1000 lb A/C condensing unit on the trailer as I did yesterday. As long as don't jump on the throttle to hard. Which for me is hard to do LOL.

becker87 · June 1, 2012

At around 75, depending on wind, usually around 16 or below. Speed kills milage.

Nvd · December 18, 2012

2010 sierra denali

1st tank, was easy on it got 625km w/87 when gas light came on, (hwy/rural and little city)

2nd tank, im still easy but am at 1/4 and im at 500km, the dic reads 13.3l/100km=17.5mpg.

im not resetting it until after next 1 or 2 tanks bc im gonna try 91 to see what happens

becker87 · December 21, 2012

Since I put my new coopers on, mileage has definitely dropped. Last two highway adventures I have bairly hit 14 @75 mph. There was some cross winds which didn't help. Going 65 or lower my mpg really jumps, to around the 16-17 range.

Nvd · May 1, 2013

well I have been running 87 esso the past 5 months (dec-april) and have been getting 14.4-14.8l/100km. Now the weather is getting warmer here I'm currently at 14.4l/100km. it dropped .4l/100km since my last fill up!, I'm continuing to use 87 till about july hopeing to get closer to 14l/100km, then will switch to 91 to see the difference.

In the winter with 87 i avg 14.7 +/-

In the summer with 87 I'm unsure as of now, will update in a few months