Tires 195/55/15 or 205/50/15 Options

[grantsfo]

I'm shopping for tires now. I have found a few interesting tires in 195/55/15, but was wondering about 205/50/15. I know clearence for 205/50's depend on tire and car, but regardless of clearence what would work better on a stock powered 1.8 with koni's, sway bar slightly lowered etc. I know that fatter tires dont always equate to better performance. Should I consider 195/50/15's to minimize rotational weight on my stock powered car?

Looking for dry weather tire I can use on street and for AX.

[Dave_Darling]

WRONG SIZE!

Tyre outside diameter should be the same as the original 165HR15.

I disagree. Having the stock gearing and speedometer/odometer readings is a nice thing, but is not necessary. In fact, it can be a nice thing to have shorter gearing. Particularly for autocrossing--you pull harder coming out of the corners, and top speed is not that important.

Also, shorter sidewalls give you more feedback about what the wheels are doing. This not only means a harsher ride, but it also means that you can actually react to what the car is doing before it's already done.

I used to run 195/60-15 tires for steet and autoX. When I switched to 195/50-15 tires, all of a sudden it was easy to "catch" and correct an spin that was just starting. I could tell what was happening as it started, not after the back end had already started to go around.


When I looked into it, it seemed as if the tradeoffs between the 205/50-15 and 195/50-15 came out about even when autoXing. You get a little more grip with the 205s, but not much. 205s are ballooned out a fair bit when put on 5.5" wide rims (all stock 914-4 alloys are 5.5x15) so you don't get as much extra rubber on the road as you would expect when you go from 195 to 205 width. And you get shorter sidewalls and shorter gearing with the 195s, plus a little less unsprung rotating mass. Apparently the trade-offs there come out to just about even on the autoX course. I personally think the 195/50s are a little better on most courses I've run.

--DD