I have recently purchased ZO6 Chrome wheels for a 98 C5. After further inspection I have noticed that the Rim is wider than the tire and a small bit of the rim extends wider out. I have an H/C installment due soon and need to verify the correct tire size for the aftermarket ZO6 Wheels.

Can anyone verify if these tires are adequate and are the tires size correct for the front & rear wheels?

A. Falken FK-451 (Front 275/40/17 ZR) $123.00
(Rear 285/35/18 ZR) $179.00

B. Sumitomo HTRZ II (Front 275/40/17 ZR) $99.00
(Rear 285/35/18 ZR) $123.00

If anyone has pictures of these tires on your vette, that would be even better for me to view!

Thanks for your help in advance.

R/

Free!

 

Those sizes are ok.
Here is what comes from the factory on a Z06, and yes the OEM Z06 wheels ARE 1" wider than the coupe and convertible wheels.

17x9.5" wheel, with 265/40x17 tires
18x10.5" wheel, with 295/35x18 tires

 

Thanks glen

You are always helpful and continue to do so! If I may ask, which of the two tires would you buy!

I like the HRZ's myself!

 

those sizes are alot closer in diameter size than OEM. They MAY cause TC codes ( I don't think so but it's worth considering).If you want to compare tire sizes go to www.1010tires.com and click on "tire size calculator" under the tech section. You'll see that OEM have a difference of aprox 3/4" ( C5's have an inch) and the tires you listed have a difference of aprox 1/3".My tires are about 1/2 and I've never gotten a code, some guys run same size front and rear and have no TC codes, other guys swear it's a problem.Good luck.

 

Now I am really confused!

 

Don't be...................

Nothing to be confused about.....

I honestly do now know about the 2 tire brands you mentioned above....

They do seem very inexpensive, which actually makes me concerned that they are indeed NOT good enough for your C5......

How about BF Goodrich KW or KDW tires. They are very nice.
Thet are just one suggestion among many others that are out there....

Here is some oinfo I found Sumitomo HRTZ II

Falken FK-451

 

I'm sorry, I'm not trying to confuse you.
You see when GM designed the c5 ( before all of us decided we could do it better and started to mod our cars) they used different diameter and width tires on the front and rear. You already knew that because you selected different tires as replacements.

Now the width can be a problem if you make them too wide because in the front they can start to rub the insde of your wheel well when you turn your wheel all the way and in the rear they can extend outside your wheel well cavity; tires can also be too wide for the rim you're mounting them on.

But the POTENTIAL problem I was trying to point out to you has to do with the DIFFERENCE in diameter between the front tire and the rear tire. When GM designed the car they not only used different width and rim sizes but also different tire diameters. Now as you know you have some systems on your car that control your rear wheel traction (TC ). As with everything else on the car your traction contrl is itself controled by a computer and the computer uses sensors to "feel" if everything is OK with the various subsystems. The computer is programed to "feel good" when it senses a DIFFERENCE in the diameter size of the front and rear tires.And if that difference "goes away" ( like you put a smaller diameter on the rear than the front ) the computer starts sending codes and may even put your car into a "reduced power mode". NOT good.

Now how close can you make the 2 ( front vs rear ) diameters to each other ?? That's where there seems to be some debate on this forum - you can do a search on "tire size" and get a gizilloion opinions. But here's what I think is the general consensus :
Never put a smaller diameter tire on the back than the front ( your choices are fine here )
Some people on this forum, who I respect, maintain that you can use the SAME size diameter on the back as the front without causeing any TC problems ( your choices are OK here )
Unfortunately, some people on the forum, whose opinion I also respect, maintain that the same size diameter will cause TC problems - they seem to think that it's sooo close that it really depends on the "sensitivity" of your car's computer

My personal opinion, that NO ONE on this forum respects, is that you should try to keep your rear tire diameter at least a 1/2" larger than the front.

With the tires your looking at you've got a little less than 1/3 inch difference between front and rear- so you should be fine.
But, just a thought, what happens if your fronts wear faster than your rears?

I only pointed these considerations out because you are "close" in your tolerences and I didn't want you to put the tires on the car and the start getting TC codes.
Only last week someone on this forum was trying to sell 2 brand new tires that he had run for only 50 miles and he kept getting codes and reduced power because they were too small.Just didn't want it to happen to someone else.

If I still have you confused just disregard what I said- my wife and everyone on this forum does that automatically.

 

I don't want to confuse the TC computer issue, but there's also the accuracy of the speedometer to contend with. What diameter did GM calibrate the speedometer to?

 

Oh ok, I got it! So what is the safest size tire I should go with then!
265/40/17 and 295/40/18 or 275/40/17 and (295 or 285/35/18). I just want to be on the safe side, that's all.

Thanks!