15x7 vs. 15x7.5

[abefroeman]

I am just writing to bitch, because there are very few cheap 7.5 inch wheels out there. How large is the .5in advantage over 15x7; which are much easier to find used. Is there a documented time difference?

can someone who has experience with both wheel sizes comment on their ability to "feel" a difference between the two?

[BudMan]

First, admittedly, I haven't run the 7.5 yet. However, with the standard 205/50 (even an oversize azenis which is closer to 215/50) puts all of the rubber on the ground with most 7". I don't think there would be much of a difference in feel or time like there is when going from a 6 to 7". A 6" wheel & the camber I run clearly shows rubber NOT on the track.

That said, it seems to be more popular to start running 225/50 for track use & I would expect to see a difference there. It's just coming up with the money for the 7.5 that is going to keep many from that zone.

Oh well - BudMan will be watching this thread for thoughts & experiences.

[Bbasso]

I also have not run on 7.5 rims, But I do use 15x7 for the choice of tires.
What I mean is there is more of a choice in an affordable amount for 7 and under then the 7.5 and wider.

Now excatly what tires will you be using or want to use? I think you need to decide what tires you will be using and then get the appropiate rims to match.
I could be way off with my thinking but don't think so.

example.

205/50-15 lowest R-comp price on tirerack is $119.00
205/50-15 lowest street tire price is $47.00

225-45-15 lowest R-comp price on tirerack is $146.00
225/50-15 no street tire avilable on tirerack and tires.com

[abefroeman]

Last year I ran 205/50/15 Azenis on stock sized rims in the stock class. The azenis are still good, but this year I will be in STS and the rules allow up to 7.5 wheel width.

I thought that both 225's and 205's would fit on either 7's or 7.5's is that wrong?

[Bbasso]

I thought that both 225's and 205's would fit on either 7's or 7.5's is that wrong?

it depends on the tire, you need to check the specs for each tire. Some say between this and that and that might eliminate your choice of a tire.

[jetydosa]

What kind of car are you running in STS, the R goes to STX (I assume you drive an R since this is ITRCA).

In STX you are allowed 8" wide wheel, there are a few of us that are in on the rota 15x8 groupbuy. We'll see how they feel once they get here.

[abefroeman]

yup, I meant STX
it is '98 ITR
and I am also in on that groupbuy,

what tires will you run on the 15x8s?
i am planning on running the azenis but i think they maybe too narrow for 8s, what are your thoughts?

i was thinking about the hankook 225/45/15s

[jetydosa]

I will initially at least run 205/50 azenis. The Hankook is tempting in the 225 but I am not sure the grip is there, I hope Falken will give us a 225 eventually!

[bbqman]

Even when compared in the same size, the Hankook is easily on par with the Falken. Obviously the 225 size will put the Hankooks into another performance level.

[Black_R]

i currently run 15x7.5's and am in on that groupbuy for 15x8's.

the 15x7 is perfect for the 205/50/15, and my 15x7.5 actually bow the tires out a bit in that size...

So as has been said before, 7" for 205's and 7.5+ for 225's.

I'd actually research what the tire mfr's recommend for minimum and maximum wheel size for those tires - and look at contact patch.....

iirc, todd00 ran 15x8's on the old azenis215 (205/50/15) and he felt that it provided more contact patch than say a 15x7. he was a national sts competitor as well...

[abefroeman]

mnfg rim range:

For the kook 225/45/15: 7-8.5

For the Azenis 205/50/15: 5.5-7.5

Looks like the wheels are a touch wide for the Azenis. Todd also agreed to this when I emailed him. But I dont think they are unsafe as Todd ran the azenis on 15x8s for a full season of autocross.

I will probabaly wear out the azenis that I have with as much track and autoX time that can, and then buy the hankooks