bigger tires less mpg? What's your experience?

I have a 6 lug stock wheel and tires. I want to get bigger ones that can fit and not rub keeping stock 4x4 lift. What's your experience with mpg after changing tires? Huge loss? barely notice?

 

The bigger the tires the bigger the mpg loss. Wide tires will drop it more then a narrow one will.

 

I believe the largest you are going to get on there are 265/75/16. They are a little taller and narrower than stock 70s. I went to 75s and did not notice much diff. If you want to calculate the height diff here is the formula 265*2/25.4*.75 or .70 + the rim diameter.

 

I don't know what the loss was but I get between 15 and 16 mpg on 265/75/16 duratracs. That is the largest size u can fit without rubbing on stock suspension. U also have to factor in the change in mileage with the larger tire, my odometer is now off about 5% compared to stock tires. If u have 17 in wheels I think u can run 265/70.

 

Stock, 17 mixed driving. 285/70R17 Niito Trail Grapplers nets 13 mixed driving.

 

I am running 285/75R16 I see a little difference but nothing really to complain about.

 

Tire weight also factors in. 10# added weight at the wheel equals 100# load. If you add 10# on all wheels its like adding 400# load.

 

so i got 245/75/r16 it looks a bit like the wheel well has a very large gap. What do you think? looking to go up slightly w/o loosing mpg (or minimal) hmm..

 

going up to 265/75/16 isn't too bad. they are only an inch taller overall and a 20mm wider. I lost a mpg or two at worst. if you off-road much it is the best improvement you can make. they fill up the wheel wells nicely. I ran like that for a while before I lifted


this is how it looks at stock height

 

this is how it looks at stock height[/QUOTE]
looks good.
how big was your lift?
keep in mind ur truck has more power than mine. I have to worry about weather or not my 4 banger can handle it properly as im assuming torque goes down the bigger the wheels get.

 

whoops didn't realize you were a 2.7. my dad runs the same 265/75 on his single cab and has zero complaints. ive driven it around some and it still gets on the freeway no problem. of course his truck is a bit lighter. if you like to off-road the benefits far outweigh any negative effects.

my lift is about 1 1/2"

 

but of course these trucks are still pretty cabable with stock size rubbers

 

I have a 2013 sport 4x4. I have a leveling kit and 285/70/17 duratracs and have lost about 3miles gallon. And that is after calculating the bigger tires by multiplying the miles by 1.07 before dividing by gallons go gas!

 

i have 265 75 16 wrangler authoritys, they lowered my mpg by about 2mpg. Others swear up and down 265 75 16 do not rub, but mine infact do rub. If i am turning and hit a bump they touch the mudflap where it bolts to the cab.

 

Stock Dunlop AT 20 fairly worn, to same size Michelin LTX AT2, lost at least 2mpg.

 

265/70/17's (32") and I lost 1-2 mpg on average over stock. I do get rubbing on the mud flaps when cranked, but I just live with it.

 

If you are worried about MPG, stick with the stock tires, or even go with an 85 series tire the same height as your 70s (narrower tread).

Bigger tires increase rolling resistance and unsprung weight. They also increase the load on the engine when accelerating (and braking).
They raise the final drive ratio, so on a vehicle that sees mostly highway driving, they stand to offer some improvement, but that is offset by the 4 cylinder engine's lower power level and needing to downshift more to maintain speed on hills.

 

I will agree (in theory) that bigger tires will reduce your MPG, but IMO it's not as much as you may think.

Your odometer works by counting the rotations of the power train, not the tire. So..... With bigger tires you are covering a longer distance per rotation.

You have to take into consideration that larger tires have a longer rolling circumference, so you are covering slightly more distance with each rotation of the tire than you were with your smaller tires.

When I moved up in tire size, I did some research on this topic and tracked my MPG for a few weeks and found that my MPG went down by approx. 10% when I moved up to a larger size tire, but due to the size of the tire, I was covering a longer distance with each rotation of the tire.

Long story (and math equation) short, my actual loss of MGP was only about 1.5% because I was covering more distance with the same amount of fuel.

Your results may differ and will depend on the size tires you use.

 

yes I would never use odometer to guage mpg after a diameter upgrade in your tires. It'd be better to use a gps to do mpg calcs.

 

or just multiply your odometer reading by the increase in circumference to figure your actual mileage