Auto X Tire input
 

I'd keep it simple and use the 245's. The 275's would be okay if you were running that car all the time as a track car and didn't mind performing the necessary mods to make them clear.

I agree that was my gut feeling. It is only a weekend/track car. I figured if I'm spending money on competition tires, why not get the most and fit a 275 and do the supporting mods?

The suspesion is stock MR if that matters?

So what would I need to do to fit the 275 tire? Or just go with the 245 because the gains would be minimal?

Since its a weekend/autox car, the real question would be how serious you want autox, and how competitive you want to be. The Hankooks aren't the popular choice for autox, and neither are the khumos.

Ive use all three, Kumhos in 245 and 275, Hankooks in 245, and hoosiers in 245 and 285. Id suggest going with the Kumhos for a decent tire that will last.

The kooks with be amazing for a while, probably the best cold performance of the bunch but without something stiffer than regular spring you'll be killing the outside edge and as soon as you over heat them they're done. The fall off is extreme, goes from wow to FML within a couple runs of being over heated.

Kumhos are known for wearing like iron. They'll take more abuse than the kooks and hoosiers and like much more heat. Its hard to over heat these, but you can if you don't manage your understeer. Ie, don't keep the wheel turned if you're understeering. It just scrubs the tires creating heat, but thats it. The older the tires get, the harder they are to put heat into but they'll keep working until they chunk or cord.

Hoosiers are the current big daddy of the auto-x world. Fastest for maybe 8-10 events, then fall off to Id guess about where the kumho's fall off too though I havent pushed one for as long as the kumhos.

I dual drove 275 kumhos for 3 years on one set with my talon. The third year was pretty bad for getting heat into them, but they never corded. I'd say 2 years at around 12-15 events a year is as far as Id run them if I was trying to make a set last.

Another thing to add, the 245s are just too small for the Evo. They get killed under the weight whereas the 275+ tires seem to survive better. My last 245 kumhos started to chunk after 120 runs. Thats much less than a years worth of runs for me.