Running 35x12.5x17 Toyo Open Countrys, on 2016 Rubi. Believe stock tire was ~32"
What should an estimate of speedo error be?
What should an estimate of speedo error be?
Speedo error after taller tire
- Thread starter zinisk
- Start date
Since actual diameter is often different than what the manufacturer labels a tire, use a GPS app on your phone and compare. You could also measure the height of your tire and use an app like jscan to set the tire height and correct the speedo difference.
Thanks JerryD. Good ideas, not trying to go for too much detail, I'm guessing 8-9% off.
I just set mine where I thought it was going to be close and then went for a drive and used my GPS to check how close it was. Then readjusted it if necessary.
WestCoastDan
JK Enthusiast
The options to adjust tire size in JSCAN offer values for every .25" in tire height.
I'm not sure if these values are JSCAN created, or ECU managed.
Just put a straight edge across the top of your properly inflated tire and measure up from the flat ground.
My 285-BFG K02s measured at 31.75"
I'm not sure if these values are JSCAN created, or ECU managed.
Just put a straight edge across the top of your properly inflated tire and measure up from the flat ground.
My 285-BFG K02s measured at 31.75"
I just adjusted mine today with J-Scan after installing the 285/70-17 BFG's. They are slightly under 33" so I set the tire size to 32.75. Was 2 mph fast according to my gps. I'll re-adjust and try the 32.5 setting tomorrow.
vaffanculo
JK Enthusiast
Exactly ...when I went from stock to 33's if I'm not mistaken it was like 3mph slower then my actual speed..
vaffanculo
JK Enthusiast