Tires: upsizing tires., z24 cavalier, kevin shaughnessy


Question
HI, I HAVE A 1998 Z24 CAVALIER. IT IS ALL STOCK, NOT LOWERED OR ANYTHING. NOW, I JUST BOUGHT A SET OF 17"X7" WHEELS FOR THEM AND THEY JUST CAME TODAY.  BUT I DON'T KNOW WHAT SIZE TIRES TO PUT ON THEM.  HERE'S WHAT I WANT.  THE WIDEST I CAN GO ON THAT RIM WITH THAT CAR, AND THE THINNEST I CAN GET IT FROM THE RIM TO THE TOP OF THE TIRE.  ALSO, WHEN THEY SAY P215/55/R16.  "P" MEANS THE WIDTH, 55 IS THE HEIGHT FROM TOP OF RIM TO TOP OF TIRE, AND "R" MEANS RIM SIZE RIGHT?  PLEASE GET BACK TO ME AS SOON AS POSSIBLE, I AM DYING TO GET THESE WHEELS ON!  THANKS ALOT BARRY!
KEVIN SHAUGHNESSY   whenirisheyesaredrunk@hotmail.com

Answer
Kevin

Your vehicle originally came with one of the following:

1)  P195/70R14 90S on 6" wheels inflated to 30 psi front and rear

2)  P195/65R15 89S on 6" wheels inflated to 30 psi front and rear

3)  P205/55R16 89H on 6" wheels inflated to 30 psi fro9nt and rear

You should check the placard on your vehicle to verify this as this is critical to the next step.  I should also mention that I have no way of knowing what the critical dimensions are in the fenderwell, and therefore how wide you can go without rubbing.

It is unfortunate that you have 7" wheels as this limits the width of the tire.  However, this may have been done on purpose to prevent the application of tires that will rub.

A P225/45R17 90 load index is the widest tire you can apply.  Note that it is extremely important that you apply at least an 89 load index.  The load index is a simple way of determining load capacity and you don't want a tire failure due to overloading - very bad things could happen!

But in case there isn't enough room in the fenderwell for this size, P215/50R17 90 load index will also work.

BTW the "P" means passenger, the 215 is the width in mm of the tire at the widest point, "R" means Radial, as oppossed to Bias Belted (B) or diagonal (D), usually refferred to as bias, and "55" is the aspect ratio - the ratio, in percent, of the width to the height.  So for your example, the sidewall height is 55% of the width or 188 mm.  And last but not least the 16 is the nominal rim diameter in inches.

I would suggest you consult with an on line club or a web site devoted to your vehicle.  Someone there probably has done all the research and can better advise you as to how much room the fenderwell has.

Hope this helps.