MrSmith

ok heres the tire issue. i currently have 225/45-17's on the car. i was thinking of getting a small width upgrade. i wanted 235/45-17's. the issue is. (i dont understand why) tire size calculator tells me i would be traveling slower at 60mph {with 235} than if i were using factory 225.

tire calculator said with 225/45-17 im doing 60mph. but with 235/45-17 i would be going 59.2 thats what i dont get. and it even got worse when i put in 245/45-17. it said i would be traveling 58.? mph. sound kinda backwards to me.

so is there a way to get wider with same rim size without loosing mph???

Roto

It all has to do with the crossection/profile ratio. I don't think there's enough of a profile range to not get a speedo error. Is under 2 mph really an issue for you? I'd be more worried arout rubbing with 245's. Don't know if that'd be the case on a 9-5 though.

MrSmith

Is 9-5 that much bigger than a 9-3??? I figured they were about the same size. but nope, its not that big of an issue. i wouldnt get 245 anyway. id get no wider than 235.

Roto

It's not so much the size, even though the 9-5 is bigger, it's about the rear suspension setup. The 9-5 has IRS and the 9-3 is a solid axle. The wheels don't "tuck in" on a 9-3.

MrSmith

ah, I see. so the Internal Revenue Service bothering my Independent Rear Suspension also. cost me money either way it go. But anywho. I wonder what that size would look like. too bad i dont see anyone wearing that size on any pics.

Roto

Is there a particular reason you want to go wider? You do know the wider you go the more it starts affecting gas milage.

MrSmith

I wanted a wider foot print. I figured a little more width would give me a tighter feel.

But no I didnt know it would give me less fuel econ. Thats 1 of the reasons i checked the speed/tire calculator.

Roto

It's a wider contact patch which = more friction. It's also going to have a couple of minor, but annoying handling effects. At least to me they are annoying. If you're not doing any racing with the car I really don't see a reason to go wider. Just get some good summer tires. I'm running Dunlop Direzza Z1 right now and couldn't be happier. They're very stiff at the sidewall and feel good overall...but the sacrifice is road noise.

MrSmith

also like the look. u know how your behind another car and u see the tires looking thin? well i like the wider look. and oh yeah. i no what u mean about the annoying handling effects. wouldn't feel as stable. that's something to think about. hmmmmm. now im having 2nd thoughts

Mountain man

Unless you have a RWD car, I'd stick with the standard size 225. The difference between 225 and 235 will be negligible on a 95 unless you have a much tighter tuned suspension. And the visual appeal of a 235 vs 225 really isn't that much of a difference. A large staggered setup like something found on a Porsche is where you notice the big track width.

If you want the tighter feel, my suggestion would be to get something with stiffer sidewalls, and more agressive compound rubber. This will make much more difference than 10mm wider tread. Just remember that more agressive tires generally cost more, wear out faster, and don't handle as well on wet surfaces. Forget trying to drive on snow. If you really REALLY want to go this route, a set of steelies with winter tires, and your OEM wheels with the summers is the way to go. The more expensive option would be to put the winters on your OEM and buy a set of fancy aftermarkets.

BTW, Roto- I got the Direzza Z1 Star Specs on my (other) car too. GREAT TIRES!