tire size question
Thread Starter
|
Senior User
Joined: Jan 2005
Posts: 172
Likes: 0
tire size question
I noticed my 99 2wd four cylinder automatic is suppose to have 225/70-15. It has 205/70-15. What i was wondering was how much is the speedo goin to be off? And say over 200 miles on the odometer, how many miles is it going to be off?? I figure it couldnt be more than a couple?? anybody know??
later chris!!
later chris!!
Elder User
Joined: Jul 2006
Posts: 601
Likes: 0
From: Denver
Visit tirerack.com - they will give you specs on the tires diameters, and you can calculate the ratio of the current size to the correct size to see how much difference there is. Then, take into account that generally Ford sets up the speedometer to read 2-4 mph higher than actual, since people tend to want to drive slightly over the speed limit...
New User
Joined: Jun 2007
Posts: 12
Likes: 0
mf11283 is right but just for future referance i'll give you the formula
to figure this out you must know the tire diameter in inches
tire diameter=2x sectionwidth x aspect ratio +rim
2540 dia. (this is a constant)
once you have tire diamter in inches for both old and new tire plug the numbers into this formula.
actual speed= new tire diameter
old tire diameter x speedo guage reading.
to figure this out you must know the tire diameter in inches
tire diameter=2x sectionwidth x aspect ratio +rim
2540 dia. (this is a constant)
once you have tire diamter in inches for both old and new tire plug the numbers into this formula.
actual speed= new tire diameter
old tire diameter x speedo guage reading.
