Yet another tire size learn needed

For Autocross only

Car: R53 Mini Cooper S JCW Wheel: Kosei 15X7 Et38

Tire sizes under contemplation:

205/50:
Bridgestone RE71R,
Kumho V720,
BFG Rival S

225/45:
Kumho V720,
BFG Rival S

Question being the RE71R is the second coming of (insert deity here) but does not come in the wider 225/45. Is the wideness worth the trade off from having a tire that is not as quick apples to apples, or will the width make up the difference? TIA

I like the idea of the extra width whenever possible. I'm not sure you'll be able to use it with how pinched those 225's will be on a 7" rim.

225 seems like it would be way too much for a 15x7" wheel. You would be tossing away some steering response and sidewall stiffness And the RE-71Rs are really that good of a tire, or at least everyone running them says so. I'd go with the 205-series RE-71R

Keep in mind that a wider tire does not mean more tire is touching the ground at any given moment, rather it means the shape of the contact patch has changed.

Also, wider tires tend to be heavier than skinnier tires.

I'd probably sway toward the RE-71

the kumhos have good grip, but there are quality issues about the delamination. It seems to be tire pressure dependent...

225 on a 7" wheel will be comically squeezed, I'd say you should rule that size out and add 195/50R15 instead.

GameboyRMH wrote: 225 on a 7" wheel will be comically squeezed

I've seen it work decently, but it depends a lot on the tires. IIRC, last time I saw it was a set of 225/45 Rivals on 16x7s. They actually sat surprisingly normally, but then again, they don't have the world stiffest sidewalls and they're pretty rounded across the tread to start with.

GameboyRMH wrote: 225 on a 7" wheel will be comically squeezed, I'd say you should rule that size out and add 195/50R15 instead.

That depends entirely on the tire, unless my 7" Koseis were wide. 205/50s were stretched and 225/50s were just about perfect.

Usually 205s are a slight squeeze on 7" wheels. A friend of mine once put 225-wide semi-slicks (Yokohama/Avon something?) on 15x7s and it looked like he was driving on a set of 4 rear tires from a sportbike...actually that image doesn't do the hilarity of it justice.

He was still damn fast on them because his car is light as a fart and they were still R-comp rubber, but at least a half-inch of tread on each side never touched the ground.

My competition has 245/255 rubber, so I was thinking wider would be better. I know the RE71r is that good. Here's to hoping.

Side note - it's worth reading up on the actual size rather than the stated sizes. I have the Rival S in 205/50/15 one a 7" rim. They are way wider than 205 - I would say 220 ish. They are fantastic and as much tire as I would want on that rim. The Star Specs run much narrower and are actually a 205..

It seems that I have read, in several places, that the Rivals actually work very well with a slight pinch.

84FSP wrote: Side note - it's worth reading up on the actual size rather than the stated sizes. I have the Rival S in 205/50/15 one a 7" rim. They are way wider than 205 - I would say 220 ish. They are fantastic and as much tire as I would want on that rim. The Star Specs run much narrower and are actually a 205..

That's a good point. I think the 205s I had were some flavor of cheapo Yokohama (dunno, scrapped them ASAP) and the 225s I had were gForce Sports.

So not cheater tires in the least...

I just put some 225/50-16 BFG Sport Comp 2s on my 16x7 Pony wheels. Tire Rack says that the tread width is 9.1". That's a pretty damn wide 225.