How off will my speedo be with these tires?

[Jason94sport]

31X10.5X15. I plugged it into a tire site & it said about 5MPH too slow. When it shows 60, I'll be doing 55. It that about right? Looking for people with real world experiences. I'm not changeing the speedo gear cause I might re-gear & I'll do it at that time.

Thanks

BTW I do 70+ most days on the HW, so I guess I might be off more then 5mph at that speed.

 

[jimbo74]

try the calculator on www.4lo.com

also, whats your gear ratio? the online calculators are only accurate to a point and mathematically, most vehicles speedometers are overshoot about 5mph.....

 

[Jason94sport]

I did. I'd like some real world numbers from people. To gauge how accurate the websites are. I have 3.27's. Right now my speedo seems accurate.

 

[zhanx]

31X10.5X15. I plugged it into a tire site & it said about 5MPH too slow. When it shows 60, I'll be doing 55. It that about right? Looking for people with real world experiences. I'm not changeing the speedo gear cause I might re-gear & I'll do it at that time.

Thanks

BTW I do 70+ most days on the HW, so I guess I might be off more then 5mph at that speed.

I have the same size tire but they are large 31's and i am only 1 mph off, thanks to the radar signs they leave around for testing. ( Stock gears in a 2000 xls).

 

[metstalker]

i have the exact same tires and your about 1/10 of a mile off on your odometer hope that helps