[KartRacer]

Has anyone notice that on a 2002 S60 AWD with 16" wheels, there appears to be a discrepency between the actual traveling speed and the speedomenter reading. We had it check out at the dealer and was told that when it reads 100 km/h the actual speed is 92 km/h. This according to the dealer is within Volvo's allowable tolerance. Doesn't this seem excessive and annoying? Any idea on how to minimize this discrepency? Does this affect the actual odomenter reading as well? Hope some techie from Volvo can help me.

 

[Gotballs]

This happened to my friend also when he put 37' super swampers on his truck. You should be able to go to the dealer and ask them to get new gears for your car.... THats wut i believe that he did.<BR>~Spencer~

 

[S.R.]

I have heard of this type of thing with Volvo's on a few occasions, but BMW is very bad with this since there seem to be a lot of owner complaints. I do know that changing wheel sizes from 205/55/16 to 235/45/17 will change the actual speed number by 1.6 km/h and will give you a 2% difference on the speedometer reading.<P>-Drew

 

[scotty_passat]

This is common on VW's, too. Are Volvo's Bosch? Might be the same system.<P>On VW's, there is an electronic speed sensor that sends accurate speed info to the ECU. The ECU then tells your speedometer what to display...~3-4 mph higher than actual...on the safe side. The odometer and trip computer gets the "true" information.<P>I have a GPS unit, and verified this (speed and distance). <P>Another way (if you have a trip computer) is to set your cruise control to say 70 mph. Then, reset your average speed on the computer. After a bit, it should more accurately display your true speed. (ie in my car, set to 70 indicated, trip computer shows an average of 67 mph).<P>Don't know of any way to rescale, sorry.<P>15", 16", 17" wheels shouldn't matter as long as the tires are sized correctly...using the "plus" concept. (they look to be)<P>Here is a cool tire sizing tool...<BR> <A HREF="http://www.miata.net/garage/tirecalc.html" TARGET=_blank>http://www.miata.net/garage/tirecalc.html</A> <P>-Scott<P>

 

[scotty_passat]

hmmm, actual the 15 and the 16 match up pretty good, but the 235-45-17 should maybe be a 225-45-17? <P>