Saki GT

Hi, I've been poking around the stickies and reading up on tires, and maybe I missed it, but is there any discussion on the differences experienced when using slightly wider tires on our cars? The reason I ask is that I see many people opting for (on MY04+) 225 over 215 and 255 over 245 on stock rims with no rubbing issues, but what is the reasoning behind this?

I can think of looks and a wider contact patch as benefits, and rolling resistance and friction as drawbacks, but is there a good reason to go with wider tires, or will I notice any difference? Is there really any point in going up one size?

Thanks, and if there's a thread on this, I'd love a link!

CoastS2k

Street only? Autocross? Track? The effect wider rear tires have on your car will depend on what kind of driving your're doing.

Saki GT

Okay, so I am looking at tire width during normal and spirited driving on roads, not autocrossing or tracking the car. I think I understand that wider rear or front tires will effect the car's turning response, but is there any benefit to going wider on all four corners at the same time?

Thanks,

CoastS2k

If you go wider front and rear, and maintain the same front/rear stagger (the difference in section width between the front and rear tires) you'll end up with more total grip, in theory.

The tradeoffs are going to be increased unsprung weight, road noise, maybe even a decrease in fuel economy. Not to mention bigger tires will be more expensive. Not sure on the exact sizes you're looking at, but you might introduce speedometer error and change the gearing of the car if your wider tires are also taller or shorter than OEM.

IMHO, if all you're going to do is drive the car on the street, your AP2 doesn't really need any more rubber. Just stick with the OEM bridgestones, they're very good.

If you're interested in getting better turn-in/reducing the AP2's tendency to understeer, I recommend an alignment change rather than tire change.

Saki GT

I'm looking at the Kumho Ecsta MX's, but I can't find their tread width listed, so my best guess is that the fronts on 215s are 8.46" and on 225 they are 8.56".

Looking at my stock Re050s, the tread width is listed as 6.7" - much narrower than the recommended Kumho tire, so to offset this, I'm thinking of fatter rear rubber - Since the Kumhos in theory don't grip as well as the Bridgestones, would getting fatter tires (at least on the rear) help maintin grip levels?

Also, I do plan to get the car realigned when I get new tires, but I'm happy with the turn-in now, and like to keep it as close as I can with the new tires.