For GS using 17" wheels will allow 7.5" width which should help with wheelspin, shouldn't it? Aren't the stock 16" 6.5" width? All the posts reference using 16" wheels. Is this because tire selection is more limited in 17"? Kumho makes an Excsta V700 in 205/40. Will 225/45 17s fit? Kumho makes them in the Ecsta V700 as does Hoosier although the Hoosier is a wider tire in the 04s than were the same size 03s and than other brands so I suspect they'd be too wide. But, the tread width is the same as on the 225/50 X 16" and the diameter is, too and people have run the 225 16"s..

There was a post about running 225 X 16" tires in front and 205 X 16" tires in the rear. The criticism was different compounds because different model tires were used front from back. What about using Hoosiers? the fronts would be 225/45s and the rears 205/40s with a 2" smaller diameter.

 

I wouldn't run 17x7.5's because it's not legal:smile:

The 17's on the Cooper S are 17x7.

My guess is that in order to move to a tire that is any wider than the current 205 16" Hoosier you would have to take a pretty tall gearing hit. In theory a larger diameter tire will have a larger contact patch than a smaller diameter tire of the same width.

I'd wager that the weight penalty of moving to 17's is such that there is no real measurable advantage.

I'd stick with the 16's simply because it's a proven setup, plus tires are cheaper.

 

Aside from the actual stock size being 17x7", I've heard that lower profile 17" wheel/tire combinations will make wheelspin worse compared to higher profile tires (of equal diameter) on 16" wheels. They should improve transient and maybe steady-state cornering speed however. Corvette autocrossers I've talked to said that the higher profile tires had better damping and allowed wheelspin to be controlled more easily (of course that was with lots more torque...).

 

I wonder with the new gearing and LSD if the 17X7 option will be an equal option now? I guess only time will tell.

 

16's , I agree with carl.

 

hoosiers 225/45/17 is almost 2" taller than the 205/45/16. combine that hit in gearing with the weight you'll gain going to 17's and I think it's a wash.

Looks like you'll have to test and find out

But, if it were my money, I'd stick with a proven set-up, call me a lemming if you must.....

 

I broke with convention and went with the 17's, running Hoosier 225/45/17. For the street I'm running Faulken 225/45/17. There is a slight rubbing issue in the rear under moderate load hitting moderate or larger size bumps on the street, but NEVER during autocross.

As for the weight/gearing issue of 17 vs 16 - seeing as how I have never run a 16" wheel I really can't compare. I just like having the bigger contact patch that the 225 provides. But that's just me.

By the way, my sig pic is from a local club that doesn't allow R-compound tires in their stock class, so I'm running the Faulken Azenis in the photo.

 

So the 225/45/17 Hoosiers fit? Have you autocrossed on them yet? Tire rack has some wheels that are 17x7 that only way 14.1 pounds - that's as light as the NZO monza. Granted each tire will weigh more, but I have to think that extra width easily makes up for the added weight and gearing.

 

Not speaking from personal experience, but I bet they would rub. This tire has a Section Width of 9.5, which is almost 1" wider than the 205/45-16. If you're not stuck on Hoosiers, the same-sized Avon and the Kumho Ecsta are about 1/2" narrower.

Other things to consider: By running this size tire (versus the 16"), you are raising the car about an inch higher, which won't help the handling any. Also, Avon is supposedly coming out this spring with a 225/40-16, and Kumho will have a 215/40-16 in the V710. Both of these tires will improve gearing, and even the shorter-geared '05 MCS has a 65 MPH second gear (from my test drive, my car is still on the boat:smile: ), so unless it's a very high-speed autox course, you don't want taller gearing.

Just my .02.

Jim Z

 

That would put the 205/45R16 at 60 MPH, leaving the 225/45R17 or 225/50R16 about unchanged. Is the lower gearing better?

Also, if the 225/45R17 fits, the 225/50R16 should as well, if not better since it has a slightly smaller section width. Of course there is the whole issue of cornering better with lower profile tires....

Does anyone have experience with either of these (Hammer?), or is it all rumor?

 

Someone at the Tire Rack test-fit a 225/50-16 Avon Tech R on their MCS last summer, and it rubbed in the rear. This was attributed to the height of the tire, not so much the width. They're figuring the new 225/40-16 will be just right.

 

Back in the D Stock days I test fit a 225/50R16 Hoosier A3S03 on my Enkeis that are 45mm offset. I decided not to run them since the tire was touching the strut when bolted up. I would have to guess you need to be running the minimum offset possible (around 42mm) to safely clear the inside, but there's no guarantee you won't hit the flare. On a car with shocks though, I highly doubt out.

Brian

 

Is that the same thing as saying "Back to the Future"?

 

Again, having never run any other set up I cannot compare 16 vs 17. I run a 225/45/17 Hoosier A3S03, or Faulken Azenis (depending on the club I'm racing with) on a 40mm offset wheel. It does rub during daily driving if I hit a moderate size bump with passengers and/or cargo. But it has never rubbed during AX given that the vehicle is empty and I do not autocross over bumps. Now, having said all of that - if other experienced AX and class champions are running a different set up, I would not argue with them. I just like the look of the 17 and I like the idea of having more tire gripping the pavement.