255/75/r17

Tacomada nailed it. Tread pattern, tire weight, width and height all affect MPG. If you are only going to isolate tire height, going from stock height to a tire with the same tread pattern, relative weight and width but one series taller, you will see very slight gains on the highway under normal driving and, unless you're an aggressive driver, will not likely see any decreases in town.

 

Post up some photos if you can I'd love to see them.

 

Well of course it's not only tire height, it's A lot of things that comes into play. Weight, height, width. Just wondering how A taller tire gets you better MPGs, because mine got worse lmao.

 

That all makes sense. I know first hand, on my last tacoma when I went to a 10 ply LT (from a P rated) I had a reduction in mileage mostly due to weight.

 

The reason is because any gains you would have gotten from the taller tires was negated by the wider tires. Your 285's are probably a lot more aggressive than your stockers and could possibly be an LT tire which means they're heavier. So you have a small height increase to help MPGs and all the rest of the factors to kill MPGs.

 

Will do, they are going in with a set of LR UCA's, OME 885's and Dakar leaf pack.

 

What wheels?

 

yeah, it's my weight of my tires that's killing me. What I mean by my post was (long day), you do get lower RPMs with taller tires but you will have to apply more throttle to keep speed.

 

Yeah, like I said earlier, I am at higher RPMs around 70 MPH with 255/75 MTs than I was with 265/70 ATs. From what I read here though, most likely my speedo is off and I'm really pushing 75 or so. I guess I should get that recalibrated. But like he said, the tread pattern and extra weight definitely keeps me on the pedal more and thats why my MPGs were decreased a little. Still look badass though and perform infinitely better.

 

If your truck is in the same gear at a given speed the rpm will be the same regardless of tire size... This is easier to see in a manual trams. But if you were to lock the auto in 1st you could see that it is the same with different size tires. What changes is the actual speed you are going.

A gps will be able to Give an accurate speed... Miata.net has an easy to use tire size comparison calculator that gives you the difference you would experience between tire sizes.

 

WTF

For a given speed, with the torque convertor locked or in a manual, the taller the tires are, the LOWER the RPM's will be at that speed.

 

For actual speed yes. But the speedo won't know you have larger tires.... so your speed will be higher than the spedometer reads. Unless you recalibrate your speedometer to allow for the larger tire size. IF you just through on a set of 255/85/16 or 285/75/16 the speedo will read the same speed at 2k rpm as it did with 265's...

Maybe I am way off here (someone give me a smack on the head if i am ) i haven't changed the tire size on the second gen. But on my first gen everything stayed consistent. Pull out the GPS and the speed would be higher than what the speedo said with larger tires on.

 

I was talking about actual speed.

For the speedo to read the same with larger tires would depend on the gearing of the vehicle and I'm still not sure it would read the same speed with different sized tires.

 

The speedo would be calibrated to the OEM wheel size and how that related to axle revolutions , no ?

The speedo would not change because you have bigger ( taller ) tires , but you would be going farther per revolution and therefore faster than the speedo reading , no ?

 

I run these tires on FJC steelies with stock suspension. No issues other than some slight rubbing at full compression while turning.

 

Did you have to do any trimming? Did you remove your mud flaps?

 

Yeah, I suppose you're correct. I think I confused myself once the speedo read out came into the mix

 

No trimming at all. I still run 3 out of 4 mud flaps. One of the front flaps was ripped off by an obstacle off road, it had nothing to do with the tires.

 

Also of note, the FJC steel wheels I am running these tires on have less backspacing than the Tacoma wheels, so they sit about 1/2" farther out from the frame and suspension.