Rim change affects?

reinier claasen · Post by **reinier claasen** » 31 Mar 2009, 07:45

Hi, I'm brand new to the volvo experience. Never owned one or personally new any on e who did but am buying one now. My question to you is the following:
The var came out with 215 55 R16 rims and tyres. The previous owner went and put 245 45 R18 rims and tyres on. Is that going to affect the car any how and is it not putting heavy strain on the gearbox?

Post by **MadeInJapan** » 31 Mar 2009, 17:05

Welcome to MVS.
tire and wheel size does make a difference in what kind of mileage is displayed on your odometer and speedometer, making them off if there is a big difference between recommended and what changed. That said, here is a calculator to use to look at different dimensions for the tires:
http://www.miata.net/garage/tirecalc.html
In your specific case, the 18 inch tires on those rims will cause you to be 5.4% slower than what you are really going, so you have to watch out on your speedometer when you fly by a cop...you can think you're under the speed limit when you're not... The other consideration is whether there is any rubbing on the fenders or not with the larger size tire. I would say that this much difference (not a lot) will probably be okay (others on this site however know more about this than I do)- there will not be much strain at all on the drivetrain, so that should not be a worry.

Post by **VCA** » 31 Mar 2009, 17:57

MadeInJapan wrote:Welcome to MVS.
tire and wheel size does make a difference in what kind of mileage is displayed on your odometer and speedometer, making them off if there is a big difference between recommended and what changed. That said, here is a calculator to use to look at different dimensions for the tires:
http://www.miata.net/garage/tirecalc.html
In your specific case, the 18 inch tires on those rims will cause you to be 5.4% slower than what you are really going, so you have to watch out on your speedometer when you fly by a cop...you can think you're under the speed limit when you're not... The other consideration is whether there is any rubbing on the fenders or not with the larger size tire. I would say that this much difference (not a lot) will probably be okay (others on this site however know more about this than I do)- there will not be much strain at all on the drivetrain, so that should not be a worry.

MIJ is correct...for the most part. In certain circumstances, the dimensions being off can affect operation of the ABS and traction control systems causing unwanted activation (i.e. ABS activates when it doesn't need to). If the speed being off, or the potential for ABS issues bothers you, have the dealer install software program "Circumference 2085 Application" (Volvo 30656219)

reinier claasen · Post by **reinier claasen** » 01 Apr 2009, 01:36

Thanks guys. You saved me from major speeding fines

That progam that the dealers load up, is that just plug and play that they plug in on your car ecu or how does it work? I was more conserned about the drivetrain affect but it's good to know it won't.

Post by **VCA** » 01 Apr 2009, 06:55

reinier claasen wrote:Thanks guys. You saved me from major speeding fines That progam that the dealers load up, is that just plug and play that they plug in on your car ecu or how does it work? I was more conserned about the drivetrain affect but it's good to know it won't.

Volvo's weird about software...software downloads are "parts"...that one costs $25.00. It's a program that changes the settings in the Car Configuration File so that all the modules know what size tires are installed...then it updates Volvo's PIE server, so the system knows how the car is configured (that way, if in the future the car needs a reload, the system knows exactly what options are particular to that car).