How much of a different tire size can be used?

[Mr_Accord]

Shopping around for new winter tires for my SAAB 93 that has a stock tire size of 215/55/R16's. Saw that the 205/60/R16's are about 20-30$ cheaper a tire depending on the brand and was wondering if the size different was acceptable without causing too much of a speed change, or messing with the traction system and transmission shifts?

Thanks

 

[otis24]

If you search online, there is a calculator that lets you put in your stock tire size and your replacement tire size. You can calculate your odometer difference at diferrent speeds.

 

[gaijinnv]

You need to be careful that any replacement tire you choose has the same Load Rating as the OEM tires.

I think your OEM tires have a Load Rating of 97, but the 205/60-16 tire size you asked about mostly have a Load Rating of 92 - not enough for your application.

HTH

 

[Kuato]

Originally Posted By: otis24
If you search online, there is a calculator that lets you put in your stock tire size and your replacement tire size. You can calculate your odometer difference at diferrent speeds.


Here's one I like: http://www.1010tires.com/Tools/Tire-Size-Calculator

 

[CapriRacer]

To reiterate, you have to be careful that the load carrying capacity is AT LEAST as large as the OEM size - and in this case that is NOT true as the OEM size is an Extra Load (XL).

And to complete the picture: If you are considering a change in size, check the rim width, and the diameter. Generally 3% is the maximum allowable deviation.

And as a general rule, one size up (+10 mm in width OR +5 in aspect ratio) is above as far as you can go without having rubbing issues.

 

[KitaCam]

here's another calculator....
http://www.rimsntires.com/specspro.jsp

 

[krzyss]

Load index - equal or higher to OE tires
Speed index - the same
Size - it must fit without interfering with other pieces of the car - ~3% is assumed tolerance.

Krzys

 

[BrocLuno]

I run 215/60/R16's on my '01 9.5 (2.3T) and they work just fine. I always thought that Saab shorted the sidewall to much on these cars. The ride suffers, but the handle is slightly better.

But in snow you need more height to clear snow on the roadway and to dig deeper as you drive, so the 215/60's are great. They are 0.4" taller than the 215/55's Michelin's I took off. I will not go back to a short tire again ... But then I live in the country on bad two-lanes and need sidewall to absorb the nasty's ...