255/75/r17

I run two sets of tires & wheels.
For my 280 to 350 mile/week commute I run the stock 245/75/16 Dungflops (30.47" & 661.93 revolutions per mile).
For off road I run 255/85/16 BFG KM2s (33.3" & 625 revolutions per mile).
With the Dungflops speedo reads 2 MPH faster than actual, odometer is dead on.
With the BFG KM2s speedo reads 5 MPH slower than actual, odometer reads less than actual because I cover more ground per revolution.
Calculating mileage off GPS miles I get 1 less MPG with the BFG KM2s. Some Hwy hills I could leave it in 5th and maintain speed on with the Dungflops I have to drop it in 4th & the ones I had to drop it in 4th with the Dungflops I have to drop it in 3rd to maintain speed.
I have to admit my Taco does look a lot better with the BGF KM2s & it's hard to put the Dungflops back on for commuting but no sense using up the off road rubber for on road when I have the Dungflops.

 

That's a whole lotta flopping dung

 

Shit now I am really confused?!!?! How can the speedo change? Or maybe I am mis-reading.

Actual speed, as read from a gps will be higher than the speedo for the same rpm if you put larger tires on. (pretty sure thats whay you're saying)

The speedometer is calibrated to read a certain speed at set axle rotations based on a fixed tire size. The engine will always turn the axle at the same speed for a given rpm and a given gear. Therefore the speedometer will always read the same for a given rpm and a given gear.

put on a set of 225/75/16, 265/70/16, and 255/85/16 and the speedo will still read the same... The actual speed be different. For the 225 the speedometer will read higher than actual, 265 will be accurate, 255 the speedo will read lower than actual.

This is all assuming gear ratio stays the same, and the speedometer is not calibrated to allow for each tire size. Easy way to test this is put the truck on jack stands. First gear at 1500 rpm will yeild the same read-out on the speedometer regardless of what tire you have sitting back there or weather you even have a tire mounted.

 

Damn straight

 

You know, you could have just deleted his post rather than admit he was right. Just sayin...

 

Stop drinking the maple syrup! It's affecting your judgement!

 

With you experience do you think the lower backspacing prevents them from rubbing?

 

I don't know; I don't have any experience with wheels other than the FJC wheels. I have seen others running these tires on stock Tacoma TRD Sport alloys, but I don't recall if any have been on stock suspension.

 

You shouldn't have a rubbing issue on the Sport alloys with 255/75/17

 

Thanks...Now to just settle on the tire...

 

Hankook ATm

 

Here are some pictures of the Silent Armor 255/75/17's with OME 885 Coils and Dakar leaf pack.

 

i decided on 265 70 r17s instead, with blackrock 17x8 rims