leungdarren

Hi all,

I have a stock 2007 Cayman S (without chorno and suspension control and other goodies).

I am currently using stock 35/40R18 front, and 265/40R18 rear tires (N4).

I found my ride really bumpy and quite harsh on the bumps, also make bumpy sounds, bounce around and stuff, I live in Hong Kong, roads here are pretty bumpy.

I am wondering if getting thicker tires can help this problem like:
35/50R18 front, and 265/50R18 rear?

And how will getting thicker tires affect my car? like handling and acceleration.

Thank you in advance!!

aviography

I'm sure you meant 235 for the fronts. Anyway, you should lower tire pressure first since higher tire pressure means stiffer side wall and you will feel more bumps.

Try 40 or 35 psi all around and see if that is sufficient.

extanker

go 5lbs lower than what the decal says on the door post and/or 17 inch rim and tires .have your front end/shocks checked. these are not the smoothest riding cars

leungdarren

Thank you! I will give it a try!

So you do not recommend changing to a thicker tire?

extanker

17 inch will help

leungdarren

If I want to keep my current rims?

extanker

more rubber[thicker] tires could help. depends how tall you go but it can slow acceleration

leungdarren

How about if I keep my current rims?

So I shouldn't buy thicker tires?

leungdarren

Currently it is 40, say I change it to 45 or 50?

aviography

By "thicker" I think you mean "taller", yes it would help but why not try lower pressure first so you don't need to spend more money.

leungdarren

Ok, I will try to lower the pressure today

aviography

NO, higher pressure makes the tire more stiff and the ride more harsh, two things you don't want when you are trying to reduce the harshness.

Try 35 PSI, if not then you will just have to get used to the ride quality, these cars are not made to be comfortable like a Buick sedan, so they will feel harsh on poor road surfaces, not a whole lot you can do.

leungdarren

Ok, I will try to lower the pressure today

GentlemanRacer

you cannot change tires to any sidewall height you want, you have to match it with section width, otherwise you get ABS and speedo differences which will eventually make your car unsafe. Recommended difference in wheel diameter is less than 3%. Going to 265/50 from 265/40 is 7.9% difference so no recommended. You will have to decrease your wheel diameter to either 17 or 16 inches which will improve the ride comfort and decrease the ride handling.

Stay within the recommended tire pressure or you will have a blow out.

The harshness you feel is directly suspension related. If you want to deal with harshness then you can

Change to smaller diameter wheels/so higher profile tires
Change shocks and suspension.
Get a lincoln, toyota or Buick

Jim in St.Louis

16" rims will not fit on a Cayman S and 5mm spacers are needed with longer wheel bolts (GT3 size)(on the front) if you go to 17" rims or the wheel won't spin. Seems that they are pretty snug against the front brake caliper. However, being a track guy, I have found that good tires on 17" rims seem to work better than the larger rims and tires are little less expensive.