Effects of speedometer

[nickiipoohz]

hey guys, just got 215/40/R17 tyres on my 96 accord. Just wondering if this will throw my speed meter off. I heard from one of my friends that having low profiles causes the speed meter to read less than the actual speed the car is travelling at. Just wondering if thats true and if so, will fitting 45 profile make it better? thanks

Nick

[raz05]

http://www.miata.net/garage/tirecalc.html

This will be helpful to u :D

[aaronng]

It depends on the overall rolling diameter. What was your stock tyre size?
This link has a tyre diameter calculator and lets you put in 2 sizes to see how much your speedo changes by: http://www.carbibles.com/tyre_bible.html

Moving to Technical.

[razaman]

Last time I looked (last year) 215/40 was a closer fit roller diameter wise than the 215/45, however I chose the 45 for a softer ride (family car), and it was still easily within legal guidlines in NZ.

Raz

[razaman]

Just found an old post that I wrote:


My old tyres/wheels were 195/60/15 which gave me:

Sidewall - 4.6in
Diameter - 24.2in

New tyres would be 215/45/17 which would give me:

Sidewall - 3.8in
Diameter - 24.6in

Whereas a 205/45/17 tyre will be closer to factory specs and have a diameter of 24.3.

Edit - 215/40/17 has a rolling diameter of 23.8

Raz

[GreekWarrior]

Just drive a little bit under the speed limit, that's what I do. :p

[wlee2]

go test out my spreadsheet

http://www.ozhonda.com/forum/showthread.php?t=35200

it tell you your speed at high RPMs you can change the tiresizes just to have a look at what your doing.. just dont actually try this on the road =P

[nickiipoohz]

thanks guy,my stock size is 195/60/R15 whereas the new size is 215/40/R17

[wlee2]

with my spreadsheet thing at 60 kmph on your speedo your actual speed will be closer to 58.9 kmph =P

use the spreadsheet i provided its pretty cool

[nickiipoohz]

thanks dude got it. thanks everyone for their help