Original Wheel Sizes

[NC2Stay]

Hi guys - need some advice.

I need new wheels. The stock wheels for a '95 LT1 coupe are 17" 8.5 front and 9.5 rear - if this is NOT correct, please let me know.

Anyhow, it seems hard to find a set in those sizes. Many I see (OE, AFS, etc.) are 9.5 both front and rear. How important is it to have 8.5 vs. 9.5 in the front? I assume that the engineers designed it that way for a purpose, so what does deviating mean - handling, etc.? And how critical is the offset?

On the other hand, from reading here, lots of guys have much bigger wheels. And with the same wheel / tire sizes I could then rotate (?)

I bought her with a set of chrome sawblades and from what I see, I am not entirely sure that those aren't 9.5 both - its not easy to tell when mounted.

So, could somebody please educate me on this stuff.

Thanks, Bob

 

[*89x2*]

Hi guys - need some advice.

I need new wheels. The stock wheels for a '95 LT1 coupe are 17" 8.5 front and 9.5 rear - if this is NOT correct, please let me know.

Anyhow, it seems hard to find a set in those sizes. Many I see (OE, AFS, etc.) are 9.5 both front and rear. How important is it to have 8.5 vs. 9.5 in the front? I assume that the engineers designed it that way for a purpose, so what does deviating mean - handling, etc.? And how critical is the offset?

On the other hand, from reading here, lots of guys have much bigger wheels. And with the same wheel / tire sizes I could then rotate (?)

I bought her with a set of chrome sawblades and from what I see, I am not entirely sure that those aren't 9.5 both - its not easy to tell when mounted.

So, could somebody please educate me on this stuff.

Thanks, Bob

In 1993, Chevy changed the regular Vettes to a more narrow front rim - changed from the 9.5 width to the 8.5 unless it was a Z07 suspension car (Zr1's also got the 9.5's up front)

My 1993 'vert was equipped w/ the 9.5's rr and 8.5's up front - they are now 9.5 all around, w/ 285/40/17 runflats on each :cool

 

[NC2Stay]

OK, but that is the question: why did they change to a narrower wheel and what do I lose by going to a 9.5? Did you notice any difference?

Just guessing, I would assume that a 9.5 steers harder and would wear the tires more on the edges. Hydroplaning in wet weather would also be worse. Alignment places might not be able to use factory specs when aligning. Etc. etc.

Bob

 

[G Winter]

Narrower tire on the front has less tracking problems. If you have the 8.5 rims on the front the tire size should be diff.

Glenn

 

[1HotVette]

Another reason that Chevy went to a narrower tire in front is to increase understeer. A car that understeers at the limit is safer than one that oversteers.

I too have a 93 and I put on 9.5 ZR-1 style wheels with 275-35-17s all the way around. Gave the car a whole different look and I can rotate the tires.

 

[*89x2*]

Narrower tire on the front has less tracking problems. If you have the 8.5 rims on the front the tire size should be diff.

Glenn

Yes - that was the reason. Narrower fronts tracked less -

 

[NC2Stay]

...If you have the 8.5 rims on the front the tire size should be diff...

Well, that is a good question! I put on the same tire sizes that were on previously, so I assume that the previous owner did it right, and thus I do in fact have 8.5 front wheels.

Thanks again, Bob

 

[tlong]

Bob, the above info is right. The car 'tracks' a little with the same size wheels. That is on the highway it wants to follow in the grooves and wanders a bit. The 8.5s in front solve that. But changing to 9.5s allows rotation. Handling is different to a small degree.

Wheel stores don't offer this. They want to go to 9.5 and 11s in the back or 9.5 all around.

I preferred to stay stock and bought some nice used CE wheels in that size. They look great.

 

[JEFNLSA]

Bob,

If you go w/ 9.5's all the way around - which is very common - you can run the same size tire on all 4 corners. With the Kumho ASX's (non-directional tire) - which you are running - you could rotate left to right & front to back.
You could go w/ 285's (or 275's...but, imo the 285's fill the wheel wells better) all the way around, which is what I had until I switched to the 11's on the rear.

I don't think you'll notice a big handling difference w/ 9.5's up front & the positives will outweigh the negatives.

Just some food for thought...

Cya,
Jeff

 

[NC2Stay]

Thanks Jeff. I am getting pretty close to having to make a decision - the Kumho's (which I do like - handling is good esp. wet, fairly quiet) are wearing nicely (not my DD, but I put a lot of miles on), but will probably not last out the year. The sawblades are, unfortunately, NOT wearing nicely and are getting pretty pitted. They look better when I wash and polish them, but turn bad very quickly. Keep 'ya posted...

Bob