speedometer and gear ratio error with plus sizing wheels - Honda Prelude Forum

ntr100 · 01-16-2002, 09:14 PM

I am wondering how much the speedometer and gear ratio's are altered when plus sizing wheels from stock 16''s to 17'' or 18''. Is the gear ratio alteration a bad thing?

Also, how would someone charge to recalibrate my speedometer with plus sized wheels?

Any problems you've experienced?

Thank you for your advise.
Num

screwdriver · 01-16-2002, 09:56 PM

click on this and fill in the blanks.
http://www.miata.net/garage/tirecalc.html

ntr100 · 01-16-2002, 10:11 PM

i wanted to know about how off my speedo will be, not about tires yo...

and i have a prelude...not a miata...

thanks for the reply though, I appreciate it.

mr.wong · 01-16-2002, 10:14 PM

Your an idiot.Go back and check the site again.I don't drive a miat either.

screwdriver · 01-16-2002, 11:22 PM

the site i posted is from the miata board and has the calculator where u enter ur stock wheel size and the aftermarket wheel size u are going to get.
it will tell u the difference at the bottom how much ur speedometer will be off.try to read more carefully. sometimes things are under our noses and we cant find them.

Neulude · 01-17-2002, 01:07 AM

Quote:

Originally posted by mr.wong
Your an idiot.Go back and check the site again.I don't drive a miat either.

ahahahahahaha..... Nah seriously though..if you do the plus sizing correctly, staying within the 3% tolerance, your speedo is not going to be affected. MORE than 3% though, WILL definately throw it off, PLUS affect your ABS function as well... Dealers will tell youthe same thing... Speedo is un-alterable (99% sure) as it is computer controlled...

For the Plus sizing formula, if you want to do it manually, go to Tirerack.com...they have the formula there...

Akimoto · 01-17-2002, 03:57 AM

http://www.greenhydrant.com/~drees/auto/tirecalc/

this is a better site.
You enter a range of tire sizes you are looking at. And you set your stock tire size. Then it will calculate how much you are off from the stock sizing in your particular range.

HTH.

kyle5574 · 01-17-2002, 08:17 AM

Quote:

Originally posted by Neulude
Speedo is un-alterable (99% sure) as it is computer controlled...

Stock speedo is off anyway. Maybe plus sizing will fix it

Some aftermarket meters (like my APEX'i rev/speed meter) can account for plus sizing and display accurate MPH. It was difficult for me to get a hold of one that didn't measure in kilometers though.

mynd_blur · 01-17-2002, 08:49 AM

Try this site...gives a lot of info

http://www.tolan-hoechst.com/cars/tirecalc.htm

Two-Five Boy · 01-17-2002, 09:48 AM

our stocks are 205/50/16, correct? Don't remember!

nuro · 01-17-2002, 10:05 AM

what are stocks on the base model?

mynd_blur · 01-17-2002, 11:12 AM

Quote:

Originally posted by nuro
what are stocks on the base model?

205/50/16 on a 6.5" wide rim

Pete · 01-17-2002, 11:17 AM

Quote:

Originally posted by kyle5574

Stock speedo is off anyway. Maybe plus sizing will fix it

Yep. I checked mine with a GPS. It's off by 4-5%. I'm switching to 205/55 tires next time. That should fix it. I think the Prelude has an Accord speedometer kit in it.

ntr100 · 01-17-2002, 05:55 PM

in response to the idiot comment...

I was joking with you. I know it's hard to discern a joke when its typed rather than told, but never the less, I was kidding with you.

I do appreciate the feedback though.