Who changed tires & lift only, what MPG loss did you see?

First I wanna say, I know I will lose MPG no matter what. The point is, I am trying to determine which factors have what amount of effect so I know what to focus on to balance priorities.
For this thread I want to focus on effective offset/stance and how much of a roll I think it plays based on peoples replies. Please only vote if you compared your MPG before making other changes. Looking for just lift + tire change, all else the same

I have a feeling based on all the research and reading tons of threads here + elsewhere that offset plays a bigger role (stance) than people realize. So for that reason I want to see tread pattern changes along with tire weight changes without any change to wheel and see what MPG people are losing. Almost every Tacoma/4R/Lexus I am seeing with exceptional MPG for its respecitive level of build is running OEM Toyota tires of some kind with positive offset. Coincidence? Lets find out.

I am looking at 17s with 285/70s cause some of the trails I want to do require it. So I only did the math here but the same thing can be applied elsewhere the numbers will be the same, just much lighter.
17x7.5 +15 has an effective offset of 80.3mm (this is the most common 2012+ Toyota OEM 17" wheel to my knowledge)
17x8 0mm has an effective offset of 101.6 (0.82 inches more stance/poke)
17x8.5 0mm has an effective offset of 108mm (1.2 inches more stance/poke)

95% of info out there about offset having a big effect on MPG is when someone is in negative offset, nobody seems to give any cares when someone has 0mm

Even 17x8 +8 or something is still 0.5 inches compared to an OEM 17x7.5 +15
Something like 17x8.5 +12 is still 0.6 inches compared to OEM.
From all the threads Ive read, most people look at that and say, hes got +12 - offset isn't a big factor, its gotta be tread or weight of tire/wheel or something else.
People look at 17x8 with 0mm and its a light wheel and they say oh that weight makes no sense to be so different, weird I cant figure it out.

...well I think its offset! 17x8 +0 is 0.8 inches more!!

Im starting to think that this has a bigger factor than what the comments/threads Ive read through seem to indicate. Lets see if Im wrong!

 

Lifting adds more negative pressure and adds drag under the vehicle, so that alone is MPG eater.

Tires can vary wildly, if you put a loud mud terrian with high rolling resistance it will burn more MPGs than a mild A/T tire.

You don't need 285's, you want them. If mileage is such a high priority get 255/75(80)R17's or stick to 265/70R17.

I saw a 5%-10% hit with duratracs and a 2" lift.

 

255/80s might be an option too, but I do want to do some trails that absolutely require 33s, even 33s might make me need some tugs if I dont wanna break anything. Im seeing what rigs people are taking Toyotas on, most are actually 35s, but im not going there. 33s are a must. Either 285/70 or 255/80 - but Im trying to balance it out because I also intend to do long road trips to other states, like I said, trying to find optimal balance. Lets be civil here. I know you cant have the best of all worlds, trying to determine which factors do more, I think some of the assumptions everyone has might be wrong. Possibly. Possibly but not for sure.

And yes obviously tread pattern matters a lot, I would assume 80-90% or so of those who got a tire but no new wheels are not running MT. Maybe im wrong, I assumed majority of those in this position are running AT, yes tread changes in there, but the tread in that varies just as much as people who run new wheels at the same time, some go really mild ATs and some go KO2s

 

Your gonna take a 5-10% hit no matter what if you lift and go to 285s. So all the other bullshit is useless. Lift the damn thing and drive it.

 

I get it, some people could care less about MPG. Whats wrong with trying to determine if stance plays a bigger role than most of us believe? Losing 5% or possibly even 10% is fine. Losing 15-20% however is not. I plan to lose more MPG in other ways too, so trying to minimize MPG loss from this while being capable. Wont be the most capable, wont get the best MPG, trying to find ideal balance. If I need to go with OEM +15 wheels to do so, Ill do it. Trying to find out.

 

I’m running a 17x8.5 -10 285/70/17 3/2 lift. 70-75mph hwy I average 19mpg, city is about 17mpg. If I drive 70 on a long hwy run 200+ miles I have averaged 20mpg( but it’s so hard to drive 70) at 80mph and above it drops dramatically. I average 350 mile per tank and usually when I fill up 17.5-18.5 gallons.

 

That is a 33

The tire calculator should be helpful

If you are worried about mpg now, wait till you see gas prices this summer

 

Offset doesn’t matter. If they stick out past the wheel wells you’re going to get some more air resistance from the tire itself but it’s negligible. The weight of the tire and the higher rolling resistance is what kills mpg.

 

255/80r17 will give you the ground clearance of 33’s and less rolling resistance. The tires are heavy E load though unfortunately.

 

255/80 in E is still about the same weight and typically lighter than C rated 285/70 but yeah

Im not sure that doesn't matter thats the point. Thats conventional wisdom on these groups but Im thinking it may matter more than people think. Yes the whole tire isn't being exposed, but a lot more of it is being exposed even still with 0.5-1 inch which is still technically "in the wheel well"

 

I think if you took factory tires and wheels and added a 1” spacer the fuel economy would be effectively the same. Weight is the number 1 factor by far. Larger diameter tires change the gearing in a sense and will also require more energy to turn.

 

Thats not a bad test. Im curious if that really would be similar MPG! Yes im accounting for weight as much as possible. Thats where balance comes in. As I showed 17x8 +0 is still significantly more stance than 17x7.5 +15 so if saving that 8-9lbs on the wheel accounts for less than being fully within the wheel well at 17x7.5 +15 but heavier wheel, maybe thats the right choice.

 

I get around 17/18 mpg comb with 285 70 17 KO2 C load - 51 lbs. I do drive the speed limit and take it easy though.