No BS: Lifted and big tires, real mpg?

3” lift, 285/75/17’s (34”), stock gearing. I’m currently averaging (according to the computer) around 11-13.8 MPG, so in reality I’m getting 12-15 MPG. However, the majority (90%+) of my driving is currently on the highway with 65+ MPH speeds.

I also noticed that I lose around the same fuel efficiency towing a trailer as I did before, generally 2-4 MPG on average.

 

285/75….with. 1.5 inches. Just filled up and got 19 around town. Have 50k now, and I think my mileage has improved over the year. I bought one of those calibration boxes installed behind instrument cluster to change speedometer to match actual due to tire size. I’ve gotten 21 mpg on highway, no wind going 65 for a few hundred miles before with cruise on. Faster speeds kills mileage. I use gas buddy application to keep track of gas mileage.

 

285/75/17 or 285/75/16? I would assume on a flat road if I set the cruise at 59-60 MPH (would be a real speed of 65-66) I could likely achieve at BEST 17-18 MPG. However many roads I drive on are not flat, my truck mainly stays in fourth, and occasionally fifth gear. If it’s in fourth and I know it CAN downshift I just blip the throttle and it increases RPM’s enough so that the truck shifts.

 

Your average seems to be very similar to mine. Technically speaker my 34’s should be 10.7% larger than my factory tires were. However, I assume due to tire deflection the overall difference is less than 10%. For easy math in my head I still use 10%, makes it easy to “recalibrate” the speedometer while driving, and I also know I can multiply by 10% and add the difference to the computers MPG and it will give me a rough estimate of what I am actually achieving.

In my case, even if I averaged 13 MPG that wouldn’t be bad considering when new I was averaging around 16-18 on a good day.

 

285/75/17 Yokohama MT
~3" lift
50/50 City/Highway
Dash reads ~12-14 MPG
Kdmax tune
Stock AT Gears
Got a Prinsu
Slimline bumper + Winch + Sliders

EDIT: - i could absolutely get better MPGs but i'd have to completely change my driving style

 

What are you overage speed limits on that side of the country? I know with ours I couldn’t get close to those numbers.

 

I actually installed converter box to correct speeds, and verified actual using GPS. My true speed matches speedometer.

 

good question - out here on the highways its usually Max of 60 - 70.

I know when i drive thru Idaho or go to Utah they got speed limits up to 80 MPH and my MPG numbers absolutely crash if i try to keep up with that

 

I was only speaking in regards to my situation. Are your tires 33’s or 34’s?

 

Speed limits here are generally 70-75 and my non-regeared truck doesn’t handle it well MPG wise.

 

To clarify, My tires are 285/75/16 in size.

 

Just went to the Subaru dealer in Plano, was a 70+ mile trip one way, and I mainly used cruise control at 70-80 MPH. Computer said my average was 15.5, so in reality it was around 16-17 MPG.

 

A whole lot of information you are asking for, but, I get about 17ish on a good day.

 

2021 Off Road (Double Cab, V6, 4WD, AT)
Rough Country Speedo Calibrator (verified with two different gps apps)
2” Spacer lift
285/70/17 BFG All Terrain KO2 Load Range C @ 40 psi
MB 701
~75% Freeway Driving @ 70-80 mph
Mostly dry Phoenix weather ~50-90 degrees from late Jan until now.
17.7 mpg.


Best mpg I’ve got with this set up was driving to Palm Springs from Joshua Tree. All downhill coasting with a few climbs. 22 mpg.

 

Love you Rig m8, which headlights are those?

 

Thank you. Stock, just pulled them apart and painted the housings.

 

Sounds like you need OVTune

 

I must have bought the worst mpg Tacoma it’s getting between 14.5 and 15.5 mpg. 13000miles on it and bone stock 50% highway 50% city. I’m afraid of what I’m gonna get with larger tires. I did get the OTT tune and really didn’t affect mileage. I drive up in Toronto Canada 253f ft. ASL, premium gas.

 

I would like to add that location should be shared with this info. Different elevations, terrain types, temperature, weather, and humidity can have impacts on fuel economy. While it may be minimal, it is worth noting. Could be the difference in a MPG or two, in some cases. Example: my MPGs in GA/SC will likely differ from my same truck and setup in Upstate NY, or Mountainous CO...

 

I love my cooper XLT in 285/75/16 and super bummed they are being discontinued for the new cooper tire that looks like a Goodyear parent company clone. They aren't the sexiest tire, but super quiet and compliant in almost all conditions.

For OP, I average around 15 mpg on my tires (can get up to 18 if I baby it under the right conditions), if you haven't recalibrated your odometer you're getting better mpg than what is showing, but heavier tires, rotational mass, etc. is going to impact mpg.