Atturo Trail Blade MT, really 35"?

[Wormydog1724]

I have a set of Atturo Trail Blade MT's 35x12.50x20R. The shop guy said they're 35" so that's what I entered as my tire size for the speedo calibration. It was 3 to 4 mph off. I played with it and settled on 33.5" to make it precisely on.

 

Are they really 35's or are they are 33's?

[Silverado4x4]

Measure them, some tire company's say there tire is 35" but there really like a 34 or something but some are right on the money, it depends.

[Texas Husker]

Website shows 34.8" diameter. not sure what pressure that is at. Shouldn't make too much difference though. What where you using for speed checking? Phone GPS or a garmin Nav unit, or actual GPS unit?

 

http://www.atturo.com/moto/trail_blade_mt under spec sheet

[Wormydog1724]

Phone gps app. I tested it against several vehicles and it's accurate as fat as I can tell.

[Texas Husker]

You can always try setting your cruise at 75 or 80. Drive through a 55 zone. Compare against impending ticket...

[Texas Husker]

But, in all reality, the best way would be to try and find a flat open 1 mile stretch that has mile markers. Set cruise at 60 and use a stopwatch to time the mile. Make a few passes and record the data. It can easily be calculated how far off you are.