Celica Forums General Discussion Exterior 19" Rims and Speedometer

I'm thinking about getting some 18s or 19s, but i'm leaning towards the 19s. Wondering how bad it will mess with the speedometer, and if the computer be reprogrammed somewhere to recalibrate the speedometer to compensate for the rims?

yeah it fucks up the ready and it changes your lift point up to around 6,100RPM and it slows you down overall, i don't know the exact ratio of how much faster you are actually going but it isn't much say 100km/h is actually 103 to 107km/h

but they look fucken sweet!

Lift is not effected by the speed of the tires, lift will engage at the same RPM regardless of speed or gear you are in.

The tires will however change the gearing ratio you have to the road, this will effect torque & the speed you go in & out of each gear. Putting larger than stock circumference tires on a car is a dumb move, especially on a 4 cylinder where your starving for torque to begin with.

get some 17 racing rims

get some 17 ligth racing rims

Roll 18 light racing rim

Featured Articles >> [WHEELS] Tire Size / Speedometer Error Calculator

This script is for comparing original equipment tire size to alternate after market tire sizes.

The following is an example to help to decode a tire size like 185/65R14
185 = tire width in millimeters, measured from sidewall to sidewall
60 = sidewall ratio, the ratio of sidewall height to tire width
15 = wheel rim diameter in inches

Wheel Speed Calibration script...
https://celicahobby.com/tech/speedcalc.html

To calculate, there's also:

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

Anyways -- If you want your celica to look the dogs dangly bits, you go with 19's. They're hella-sweet, and fit the celica perfect. I'm totally lovin' my 19's!

When I bought my 19's I did a little math to find out how far off the speedo was and it turned out to be almost nothing. using Distance
---------- = Rate
Time

I came up w. a 2 mph difference at 35

and a 4mph difference at 65

So basically you have nothing to worry about