255's and 3.73 gearing

[Captm]

Finally went with new tires and wheels (BFG KM2 255/80/17 w/ Atx Mojave's) for my 05 Tacoma. Down the road I'll regear and add ARB lockers but for now it's stock with the 3.73. According to the chart at http://www.tacomaworld.com/forum/tirecalc.php I should see a increase in mpg but a loss of power. What have others experianced with 255's and 3.73 gearing on their tacos?
Cheers

 

[trump]

I can't speak about second gen results, but will say that you should question the logic of anybody that suggests that you'd see increased gas mileage.

 

[bat]

question the logic of anybody that suggests that you'd see increased gas mileage

I am going to need tires soon and I just can't see putting 255 on without a gear change, so what I need from you CAPTM is you get 1 mpg better and love the tires

 

[Desert Dan]

Lets see some pics of your 255 x 80 17 KM2s. Are they about 33" tall.

I running 255 x 75 x 17 GY MTR and haven't noticed much change in MPG in my 4R.

 

[Captm]

I can't speak about second gen results, but will say that you should question the logic of anybody that suggests that you'd see increased gas mileage.

But I saw it on the INTERNET - it has to be true :xxrotflma

Tires are 33 1/4 @ 80psi and 82.5# for tire/wheel combo. My take offs are 265/65/17 =30" at @44 psi and 61.8# for tire and factory wheel.

 

[p nut]

Even going up to 32's in my 4.10 geared Tacoma resulted in a 10% loss of MPG. I would think you would see similar losses, if not more since you got MT's. Looks good, though.

 

[JCMatthews]

Why 80 psi? These tires should be run at a slightly less air pressure than the stock tire size due to them being larger. If not you will wear out the middle of the tire tread. Not to mention how rough the ride will be.

 

[Andy@AAV]

I'm running those tires on a 2010 with the same gears. I actually gained a small MPG on the freeway but lost about the same around town. I still average about 16.5 overall which is right where I was stock. With the stock tires I actually got worse gas mileage running 75 on the highway than around town...

Forgot to add I have a manual transmission which has a lower top gear than the auto.

 

[Captm]

Sidewall rating of 80 psi is how they were installed, I'll be adjusting according to the ride. They steer very fast, on the freeway the ride and noise level is much better than I was anticipating. Speedo vs GPS = 60/63

 

[trump]

Speedo vs GPS = 60/63

Don't forget that difference when calculating your mpg. Lots of people forget that.

 

[Mrknowitall]

On a MT truck, because of the smallish OD, the highway milage really might improve a little (because of the lower effective gearing) but I would expect that at best you'll compensate for increased rotational mass and greater wind resistance. That said, with a 6speed I'd probably call it good, while an AT would probably benefit from 4.10s. Numerically, that ends up a little deeper than stock, but it will help compensate wind resistance, roational mass, etc. to keep the truck locked in OD more of the time.

 

[Captm]

Thanks Mark, I would have overlooked that. I'll use the GPS for my calculations.

 

[trump]

Thanks Mark, I would have overlooked that. I'll use the GPS for my calculations.

No worries. I apply a 6-7% penalty on my mpg calculations... of course that's mostly the gearing (4.88s) causing the big error. Need to correct that still.

 

[Andy@AAV]

My speedo is recalibrated and verified by GPS so the MPG I posted is accurate.

I run 40 PSI, even wear for the first 15k miles.

 

[trump]

My speedo is recalibrated and verified by GPS so the MPG I posted is accurate.

I run 40 PSI, even wear for the first 15k miles.

Just to be clear, that wasn't meant as a dig on you, Andy. Just something that I've commonly seen.