2014+ Gas Mileage (MPG) Topic

hutch08 · February 22, 2015

Temps have been creeping up closer to 0*C (32*F) for the last week or so, less warm up times... noticed an improvement over the last 100km. Up around 17/18L/100km.. that's like 13/14mpg. Not the greatest but beats my original 11/12mpg I was getting at first. I know it'll never get to 23mpg but even if I get up around 18/19 in the summer months I'll be pretty happy.

GPGuy · February 23, 2015

Avg 19.5 MPG with true dual exhaust, CAI (Airaid), factory tires (soon to be upgraded to Michelins), 28k miles and 93 octane with 60-80 deg temps. 87 octane, below 60 deg temps and mileage goes down to 14-16MPG. Pulling horse trailer......11-12 MPG. Every once in awhile I'll get a good load of fuel and MPG will avg 22 for that tank. Driving 3 hours at 80 mph on freeway from Dallas after duals were installed I hit a "Best" of 26.1 MPG!

Did you have your truck long enough before installing the true duals to notice what the MPG was? I was talking to a guy at a muffler shop here who claimed that his true dual system he installed would yield a 3 MPG improvement.

Mutedduck · March 3, 2015

Just bought my 15 Sierra Club Cab, 5.3 Z71 with 3.08 gears. I'm averaging exactly 15mpg for the life of the vehicle at 2121 miles. I think that is fairly great mileage considering I bought the truck with 250 miles and proceeded to head to Atlanta towing my 16ft car hauler with steel deck to pick up a pair of Camaro's. 71 and 72 models.

I had my friend tow another car hauler with his 13 Ram Double cab 4x4. Light load down at around 450 miles we both averaged around 15 mpg and loaded headed back I averaged about 13.2 and he averaged about 13.5. He had the better rear gear than my truck so I think that counts for the slightly better mpg on the return trip. Both trucks performed about the same if you ask me. I never hauled ass and left him and visa versa. We were averaging a net speed of about 78 mph on the return trip too.

I haven't had a tank of fuel in her yet where I haven't had to tow my trailer or haul some stuff around. When I did go on a decent trip of about 120 miles light load I averaged about 18 mpg, but had to have it in Auto 4x4 because of road conditions.

I filled my truck up just a few days ago and just after I filled it, I get a call from my brother to come pick him up because the wheel on his 69 Camaro came off on him while driving in the next town over. I hauled my trailer over there, ended up putting new studs on his car and he drove on home. I returned home and went to work the next day. He borrowed the truck to take parts to his body man and run some errands. A mixture of towing, hauling and stop and go driving with 142.5 miles took right at 7.2 gallons to fill up. That is just right at 20mpg. That is fairly good mileage out of a giant shoe box with wheels.

I have no plans on lifting the truck or putting big tires on it as it is also a family vehicle, and from personal experience it is a B**ch getting a car seat in and out of a lifted truck.

That being said, I wonder for those of you that have lifted your trucks, have any of you considered the fact that you have a 6l80 and it sounds as though it is an upgraded version of the 4l80, if you could do a torque converter swap. I know the factory converters on the 4l80e transmissions were huge and netted around a 35hp loss over the 60e. Just thinking it could get some of your power back.

Or if you wanted to increase mileage a smaller converter would help there to as the rotating mass would be less. Maybe a converter, dual exhaust and maybe one range hotter spark plugs would bump up the mileage. Food for thought for those who don't care about their warranty.

Wormydog1724 · March 15, 2015

Not bad for a 6.5" lift and 35" tires. 5.3L

Mike1220 · March 15, 2015

Not bad for a 6.5" lift and 35" tires. 5.3L

How?! Are thise "bests" from before your lift? What do you avg each tank?

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Edited March 15, 2015 by Mike1220

GPGuy · March 16, 2015

How?! Are thise "bests" from before your lift? What do you avg each tank?

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That's insane with a 6" lift...

Wormydog1724 · March 16, 2015

Leaving New Mexico coasting down mountains and having a tail wind really helps.

mjj · March 17, 2015

I get 99 mpg in V4 mode going downhill. Haha, just joking around.

Yesterday my last 25 was 19 mpg and last 50 was 17.2 mpg. Mostly flat highway 55-70 mph and using E85 (69%). No lift but larger heavier LT285/70R17 tires. I think the best I've ever gotten so far on E85.

GPGuy · March 17, 2015

I get 99 mpg in V4 mode going downhill. Haha, just joking around.

Yesterday my last 25 was 19 mpg and last 50 was 17.2 mpg. Mostly flat highway 55-70 mph and using E85 (69%). No lift but larger heavier LT285/70R17 tires. I think the best I've ever gotten so far on E85.

That's pretty impressive on E85!

mrbadwrench · April 5, 2015

'14 5.3 4WD 3.42 axle

With factory tires, 21 highway/18 average/15 city

Now with Duratrac tires stock size, 19 highway/16 average/14 city

wurgs · April 6, 2015

On this tank DIC says 20.5 mpg. I have 264 miles on this tank, about 50 miles in town and rest at 60-70mph.

51 ashton · April 8, 2015

Do a input vs output for a more accurate mpg instead of a calculated mpg based on a expensive vacuum gauge. That's how I do it. You may be surprised or depressed on your findings. It's a shame in this day and age to get this kind of fuel mileage. They can add all this new technology and make things smart or so they say but in the end we still only get 15.8 mpg (that's what I get) and that's depressing. I got better mileage with my 86 sierra with a 350 in it.

Edited April 8, 2015 by 51 ashton

towdog333 · April 8, 2015

Do a input vs output for a more accurate mpg instead of a calculated mpg based on a expensive vacuum gauge. That's how I do it. You may be surprised or depressed on your findings. It's a shame in this day and age to get this kind of fuel mileage. They can add all this new technology and make things smart or so they say but in the end we still only get 15.8 mpg (that's what I get) and that's depressing. I got better mileage with my 86 sierra with a 350 in it.

With all this pollution crap they put on the engines and with winter and summer blends no wonder mpg sux

brocka · April 29, 2015

3.23 gears, 6.2L engine, stock tires, mostly highway, using 91 octane from Valero

Crf450r420 · April 30, 2015

Had a 2015 6cyl 4x4 CCSB rental for a week. 3.42 axle so the same as mine but smaller tires. It was easier to run around town and keep 17 mpg but over all only 3 or 4 better than my 6.2L. If the V8s had start stop there would be almost no advantage to the V6 motors as the big difference is how fast 25 mile log drops setting at lights and in drive throughs. I also needed more pedal to get going at the same rate.