7", 7.5", or 8"

[NJSHO]

Is there a noticable performance difference between a 17 x 7, a 17 x 7.5 and a 17 x 8 wheel? I have found a set of reasonably priced 17x 7 rims that I think look good. My intention is to put a set of summer/autocross/track tire on them (if such a combination exists) and use them for all three purposes. Is a 7 in wide rim worth upgrading to or should I keep looking for a deal on rims that have that extra .5 or 1 inch?
Thanks

 

[SuperG]

I have 16x7 and use them on the track with 225's. I also ran the 225's on the stock 6" wide slicer...7" is WAY better. However, I would prefer to go at least to 235's but am not comfortable with 7" wide wheels. Also, with the larger wheels come shorter walls, therefore, a little more stiffness. Probably better for the track, but a little stiff for normal driving...for some

I am not sure that 7.5" is wide enough, either...hopefully someone else will chime in.

 

[Yamaha V6]

Wheel Diameter, Wheel width, Wheel Weight, Tire width, and Tire weight are the big factors aside from Tire Performance factors.

Rule of thumb: Wider is better for handling, Wider USUALLY means heavier, resulting in lower acceleration.

My 17x8 wheels w/ Kumho V700 track tires were a heavy combo (~51 lb per corner, IIRC). However, the 245/45-17 track tire is a very good thing on a SHO at speed under heaving cornering & braking. Acceleration, well, I hope you have a blower on the car.

I just sold my summer performance combo - 17x7 Team Dynamics Pro Race 1 wheels, in 17x7, with 235/45-17 Toyo Proxes T1-S tires. These tires are fantastic summers / autocross tires (Miata guys love them at Auto-X). The TD wheels were 15.75 lb each, and the TD + Toyo combo was ~41 lb complete. Compared to the 245/45-17 17x8 combo, that's like removing 280 lb static weight from the car - it makes a difference.

Assuming both tire combos were the same summer tire, and the only difference was weight vs. 1" wider track & 10mm more on the tire, I'd rather have the 235/45-17 tires on the lighter 7" wide wheels for the combo you mention. For all-out track use, I'd rather go as wide as you could on our cars.

 

[Yamaha V6]

Oh, and I ran 235/45-17 on my 17x7.5 TD wheels on my white 95 MTX... EXCELLENT combo, but heavy wheels (they were 24 lb each).

 

[NJSHO]

235 wasn't to big for a 7" rim? Many online tire places say that a 235 should be used for 7.5" and up.

 

[GreenStreak]

Most people run 225's on 6" Slicers, so I don't see why 235 would be a problem on 7" wheels.

 

[SuperG]

235 mm is 9.6" wide. There may be a good amount of sidewall flex.

 

[Yamaha V6]

Depends on the tire too. Remember this is a 17" wheel, vs. a 16" too.

The 235/45's are not really "bulged" over the sides of the 7" wheel, to be honest. Sure, I like the stability of a wider wheel, but feeling that you "have" to go with a 225 tire on a 7" wheel is bogus. Also, the 225's are on the Gen 3 6.5" wheel.

yes, the 225/55-16 is a wider than optimal tire for the 16" slicer, but I've never had any serious issues with it either.

Again, if you can do it, go wider. If you feel the weight of the wheel isn't worth it, it'll work.

Also FWIW, I know people running 245's on 7" wheels, and they report no issues. That's a little wide for my liking though.

 

[RJ-92]

Gary, any Idea how much the T-bird SC wheels weigh compared to the slicers?

 

[PROPHET]

Go wider on a 16" rim, weight always matters.

 

[NotSoSlowSHO]

Just find big AND light wheels

I just sold my summer performance combo - 17x7 Team Dynamics Pro Race 1 wheels, in 17x7, with 235/45-17 Toyo Proxes T1-S tires. These tires are fantastic summers / autocross tires (Miata guys love them at Auto-X). The TD wheels were 15.75 lb each, and the TD + Toyo combo was ~41 lb complete.

Yippy
I look forward to their arrival!

 

[GeneSHO]

Gary, any Idea how much the T-bird SC wheels weigh compared to the slicers?

1991 Thunderbird Super Coupe 16X7 wheels weight in at 21.45 lbs.
'91-'95 16X6 SHO Slicer wheel weight in at 18 lbs.

I use the Thunderbird SC wheel for winter use. Painted gun metal grey with Pirelli P210 225/55/16 Winter Sports. Can out handle all those "unstoppable" SUV's on the ice and snow.

 

[SuperG]

Yup, them T-bird wheel's is heavy! But really not so bad, considering their a whole inch wider. Of course, one of the restrictions that must be considered about 16" wheels is brakes...the choices are somewhat limited.

 

[jedhead]

I have 17X8 OZ Racing Superleggra with 235/45WR-17 Yokohama ES100. Each wheel and tire weigh 43lbs each. My wheels are 2" wider and 1" taller and weigh less than the stockers.

Bob

 

[Yamaha V6]

Actually, a 235/45-17 is smaller in diameter (25.33" vs. 26.15"), which'll be better for acceleration too.

Common hypothetical diameters:
215/60-16 = 26.15
225/55-16 = 25.75
235/45-17 = 25.33
245/45-17 = 25.68

 

[Yamaha V6]

re-read, you were talking wheels being taller, not tires. My bad.

 

[jedhead]

My overall diameter diameter went up slightly because I had 225/50ZR-16's on slicers before.

24.9"

Bob

 

[RJ-92]

My overall diameter diameter went up slightly because I had 225/50ZR-16's on slicers before.

24.9"

Bob

How did you like them? I am running 225/50/16's now. They love acceleraton but they do roll quite a bit on the wheels.

 

[jedhead]

how did you like them? I am running 225/50/16's now. They love acceleratonbut they do roll quite a bit on the wheels.

I like them enough to go thru 2 sets of BFG CompT/A and 2 sets of Dunlop SP8000. The only down side for me was that I scraped everything with my front bumper cover and scraped my subframe connectors on speed bumps. I also have SS Linears with Konis and the 225/50ZR-16 made the car sit very low. I realize now how much the bulge in the sidewall effected the turn in. With the 17" OZ wheels and Yoko's the turn in is immediate; a huge improvement IMHO. One downside was that I weaved slightly for a while on the freeway until I got used to the instantanous response.

Bob