Averaged 12mpg on road trip, expected better

FirstAscent · January 6, 2020

Try it with a gps tracking your miles since your speedo/odo is wrong. Then you will have an accurate mpg number. If you hand calculated 12.7 with the wrong miles maybe that is actually 14-14.5. If you were driving 70+ i’d say that is pretty reasonable considering the lift and tires. Also i don't recall if you said any wind on the trip. That will hurt you too. I have had trips that changed 1-2 mpg with my speed and winds. Also winter gas right now could be a factor.

Basically there is a whole slew of reasons why your mpg sucked but first check it with the accurate miles then start analyzing everything else. Just my approach.

Good point, I’ll have to track it with gps next time I know I’ll be on a good stretch without traffic. Yeah if I got a realistic 14+ I could go with that due to the lift and tires.

Bobv07662 · January 6, 2020

"I get less mileage with larger wheels an tires. "

Duh!

FirstAscent · January 6, 2020

"I get less mileage with larger wheels an tires. "

Duh!

Well of course I know that, but it seemed like MORE of a drop than expected

Grumpy Bear · January 6, 2020

14 hours ago, FirstAscent said:

Well of course I know that, but it seemed like MORE of a drop than expected

Know what thought did?

Thought wrong!

Manufactures spend huge sums on compliance and everyone on the planet thinks they are smarter than the data. GM has a windtunnel. How about you?

Edited January 6, 2020 by Grumpy Bear

swathdiver · January 6, 2020

On 1/3/2020 at 9:48 PM, FirstAscent said:

No my speedo hasn't been calibrated to account for the 35's.

Garbage in, garbage out. Go on Google Maps and plot your trip from gas station to gas station and use those miles against what you pumped. Then let us know.

Belo · January 6, 2020

On 1/2/2020 at 11:29 PM, spizike9 said:

Lifted on 35s with the 5.3 and you thought you’d get better mileage than that.

yeah this is all I had to know.

FirstAscent · January 6, 2020

16 hours ago, swathdiver said:

Garbage in, garbage out. Go on Google Maps and plot your trip from gas station to gas station and use those miles against what you pumped. Then let us know.

Didn't think about checking it that way, I'll have to make a trip up to the mountains and I can test it then.

NeverCold · January 7, 2020

Im stock and my fuel econ at 60 vs 70 is nearly 25%. Wouldnt be surprised if lifted with 35s it's more than that.

FirstAscent · January 7, 2020

Im stock and my fuel econ at 60 vs 70 is nearly 25%. Wouldnt be surprised if lifted with 35s it's more than that.

Dang! Big difference from 60 to 70!

bshort · January 7, 2020

On 1/3/2020 at 2:59 AM, Thomcat said:

The RST comes stock with 18" tires and a 3:42 rear. When you order the larger the dealer installed 22"s as an option the RST comes with a 3:23 rear and steel transport wheels.

Is this something new for 20? In 19, max tow was the only way to get 3.42 with a V8.

L86 All Terrain · January 7, 2020

Regear the truck. Put on 33's for next road trip etc.

My 6.2L on 33's gets about 15-16 highway when I am travelling fast. I wouldn't expect it to get any more than 12-14 on 35's @ 70mph.

Guys telling you that these trucks get 23-24 mpg are full of it or just really suck at math, nevermind the ones on big boots. Maybe if your 2wd V6 on a 40mph highway you can get 24mpg. The only way I can get up around 18-19mpg is to average less than 40mph over an extended time.

Road surface, tire tread and pressures, speed, stop frequency, wind resistance (bikes hanging over the tailgate) will all help reduce your economy. If your rocking a lifted truck on 35's and you are anywhere between 12-15mpg you are doing pretty good.

redwngr · January 7, 2020

On 1/3/2020 at 9:48 PM, FirstAscent said:

No my speedo hasn't been calibrated to account for the 35's. GPS at that speed had me about 5mph faster. So that would net me slighter better mpg but maybe .3 extra?

I always thought cruise control helped with mpg? so good to know. However, when my girlfriend was driving during the portion of the trip she never uses cruise control and it honestly didn't change much. Looking at my fuel logs during the trip it was anywhere from 11-12.7mpg

All logs were checked manually using pump numbers and odometer miles. There's always potential for errors but after 10+ fill ups and getting the same results, I think it's pretty accurate.

@blckblt It's a new 2019 Silverado so there "shouldn't" be any maintenance issues affecting the mpg. It now has 8k miles so plenty broken in by now.

Next time I get a stretch of open road I'll have to keep it at 60mph and do a mpg test then, now I'm curious to see how much it affects it.

Many years of playing with it makes me believe cruise does help with mpg.

(I'm a compulsive fuel usage recorder)

It's Tim · January 7, 2020

Least expensive option:

Don't worry about mpg, just enjoy your ride.

redwngr · January 7, 2020

59 minutes ago, It's Tim said:

Least expensive option:

Don't worry about mpg, just enjoy your ride.

Monitoring it and worrying about it are not the same thing :driving: .

I blame the '70's fuel crisis.......

Edited January 7, 2020 by redwngr

It's Tim · January 7, 2020

11 minutes ago, redwngr said:

Monitoring it and worrying about it are not the same thing .

"Fuel economy" was a solution in search of a problem invented by the union of concerned scientists.

The same bunch of busy bodies that forecast the impending ice age in the 1960's, global warming of the 2000's and last but by no means certainly any less important, climate change.

Edited January 7, 2020 by It's Tim