2007-01-26 15:43:11 · 8 answers · asked by knada242 2 in Cars & Transportation ➔ Other - Cars & Transportation
Measure the circumference of your current tire,#1,and then the circumference of the new tires #2. Dividing circumference #2 by #1 will give a ratio, something like 1.15 - all you have to do is multiply you speedo reading by the ratio to get an idea of your actual speed.
2007-01-26 15:53:38 · answer #1 · answered by jack w 6 · 3⤊ 0⤋
Why are you increasing the size of you wheel/tires? To truly answer this question we would need to know you original wheel/tire size and what you are trying to accomplish!
If you wanted a wider tire, say, going from a 225 to a 245, then reduce your sidewall ratio from a 50 to a 45. So if you started with a 225/50/17 (225mm wide /50% of the 225 high/on 17" wheels) you could go to a 245/45/17 or even a 245/35/18 (jumping to a 18" wheel) and they all would be about the same diameter. This by the way is called plus sizing on tires.
And a word of WARNING I am just pulling numbers out of thin air as an example. If you want work this out for your car, any reputable tire shop should be able to help you or go to the tirerack.com!
2007-01-27 00:25:41 · answer #2 · answered by aural 1 · 0⤊ 0⤋
I went from a 165 to 180 in my truck and the speedometer was off by 5 mph at 70 (it read 65 on the dash but I was actually going 70 mph). It decreases the odometer as well which isn't bad when you sell it.
2007-01-26 23:52:53 · answer #3 · answered by P K 3 · 0⤊ 0⤋
dont listen to the 225 to 235 crap. thats width. width dont mean heght. you have to look at the 70 or 65 or 75. the series of the tire if you will. thats the percentage of the width which equals the height. say you have 235/75 like me. the sidewall profile is 75% of 235 which = 176.25 then you convert that to inches. double it "two side walls" (top and bottom) then add rim diameter hence a 235/75R15 would be a 28.877 inch tall tire. go to this site for conversion. 235 is a millimeter measurment.
http://www.nettam.com/convert.html
millimeters to inches.
1.width times profile %
2.convert that number to inches
3.double it
4. add rim diameter
5. do that ration crapola.
6. should work
2007-01-27 00:28:13 · answer #4 · answered by coujoe56 2 · 0⤊ 0⤋
Figure on about 5 mph for each tire size . . .
205 to 215, speedo will drop 5mph
205 to 225, speedo will drop 10 mph
205 to 235, speedo will drop 15 mph (If it says 60, you are actually doing 75).
I have an 85 Nissan pickup which had 235's on it (speedo read 60 - actual 65 mph). I just put 215's on it (speedo read 60 - actual 55 mph). This was an overall drop in tire diameter of about 3 inches.
2007-01-26 23:56:49 · answer #5 · answered by Say What? 5 · 0⤊ 1⤋
The answer depends on the size of the original tire.
Think about it this way: If the original tire is the size of the room you're in five inches won't mean much; however, if the original tire is the size of a walnut five inches is a huge difference.
2007-01-26 23:53:42 · answer #6 · answered by Dona A 3 · 0⤊ 0⤋
there's no way to really know for sure on this , i changed mine and it threw it off around 8 miles per hour,enough to get pulled over for speeding ,you,ll just have to clock it and see how much it does throw it off, i actually had to clock mine to keep from paying a ticket,good luck,i hope this help,s.
2007-01-26 23:51:55 · answer #7 · answered by dodge man 7 · 0⤊ 0⤋
it will increase by few miles but you got to adjust the speedometer
2007-01-26 23:49:36 · answer #8 · answered by mariozielu 2 · 0⤊ 0⤋