Fat Tires & Speedo

[DrewTheBrave]

I just put some 17" Monte Carlos from a Passat on my Rabbit with the stock 235/45 tires. I'm just curious how much my speedometer will be off with the new tires/wheels. I calculated the total diameter of my stock 15's with 195/65 at 634.5mm and the diameter of the new 17's with 235/45 at 643.3mm. The new circumference is about 27.65mm greater.

Now that I'm covering more ground per rotation, how much will my speedometer be off?

Pics for clicks:

 

[Grmncrsnbr]

http://www.rimsntires.com/rt_specs.jsp

 

[DrewTheBrave]

Nice. It's only a 1.5% difference.

Thanks for the link, Grmn. :thumbsup:
I've used that calculator before, but I never knew it had info about rolling speed.

 

[Grmncrsnbr]

NP dude.

 

[IEFreshSide]

Did you have any problems with rubbing on such wide tires (235's)? Cool conversion on your rabbit. Including the bumper?

 

[zrickety]

Compare it to gps, there is an impulse number you can change in the instrument coding that will get you close.

 

[ViRtUaLheretic]

I run 245x40x17s and sit at ~24.5"FTG and dont rub

p.s. epic bump

 

[bmpgti07]

This is actually a real thread?

 

[Elliott]

No it's a fake one.