Got some bigger tires and mileage is now horrible

Bigger tires equal more weight, and that takes more energy to turn, etc.

 

Once again, I just got a little under 21mpg. 99’ 2.7L 4x with heavy a$$ 265 E-Rated tires.

297miles on the tank and I filled a little over 14.3 gals, 20.8mpg

Truck has over 335k. If you’re getting low mileage something must be wrong or you have really tall gears, or you tach the thing out.

 

That’s interesting!
What size tires and rims are you running?

 

go easy on the gas my friend.

 

Im running E-Rated KO2’s at 26psi 265/75r16. On Steel American Racing 16x7 wheels.

2.7L 5 speed Manuel. I think with 4.10 gears. It might be 4.30, I haven’t checked.

Tires we’re on the truck when I bought it. I just purchased some 15” 5x8 Method Wheels and 32x11.50 KO2’s C-Rated. Hoping to keep 21mpg and get a better ride.

 

Here Tacoma World's tire calculator:
https://www.tacomaworld.com/tirecalc

You can find it at the very bottom of the page or in the Mods & Tutorials section of the upper menu

 

Thanks. Yeah I've gone through the calculators to adjust for the different size of the tires.

 

Thanks. Yeah if you're getting that kind of mileage with that setup something is definitely wrong with mine! Got 9.5 mpg out of my last tank of gas. I switched back over to my winter 15's to see if it goes back to normal. Just realized a previous owner swapped the transmission out, looks like it is an A340 out of a 2.4l Toyota truck. So the gearing on that may not be able to deal with the bigger wheels.

 

somethings right!
Same mostly here on my 01 3rz manual 211k
265 75 16 sl w/oem alloys with recent 1.75 lift all around, consistent 19/20 hwy 60-70. Gps is spot on now, before with stock 265 70 was off a bit.
Surprisingly didnt lose much mileage wise, anything getting 20 is good enough for now.

and just because:

 

I put a size bigger tire first and lost 1 mpg. Lifted and lost another 1 mpg. Ethanol? Seems like another.

Nature of the beast, I guess.

 

Oh you have an auto. That could be the reason, but 10mpg less than my Manuel doesn’t seem right.

 

I went from a Michelin to a Toyo on my 99 Tacoma SR5 4x4 running 31 x 10.50 and I will never go back to a Toyo. I am not saying they are bad tires at all but my MPG had me baffled. Toyo had way more aggressive tread vs the Mich an they discontinued the Mich that I literally had on so long they wouldn't pass inspection from dry rot. Now with gas as high as it is I sure wish they still made them. Its crazy how simple little changes can make such drastic drops in MPG. I don't offroad enough and now that I live in NC dont have the weather to warrant changing to the Toyo's I chose but I am paying for it now.

 

I'm guessing the larger and heavier tires (looked up the Toyo's look like they are LT at 44lbs each, not the heaviest but not light) make the truck more sluggish and to compensate you are mashing the gas harder to match the performance you are used to. I mean I went to 255/75R17s on my 2.7 around 67lbs per wheel/tire but with my driving style (granny) I still get 19s local and low 20s highway. My stocks were 53lbs per corner.

Might just need to ease up on the pedal a bit and accept a slower acceleration with these tires. Oh and tread of course impacts mpg, passenger car tires get better mpg than A/Ts