bigger wheels higher pressures?

[Jaff]

Not clio related but its been bugging me, my C4s standard wheels were 205/50/17, and were 36 psi front and 30 psi rear.

ive upgraded to 18 inch wheels (225/40/18) ive been running them at the same recommended pressure,s but i cant help but think they always look flat at the front so much so i check the pressures more than i check my fuel.

should i be running a higher pressure with the bigger wheels?

 

[sideways danny]

pressure is pressure is pressure. if the weight of the car hasn't changed, the pressure doesn't need to

 

[fraserd007]

As danny said. It is what it is. pounds per sq inch.

 

[murcod]

You would need to be careful that you don't run them too low or else you'll be at risk of damaging a rim on a pothole etc.

I have always found the lower the profile tyre the more pressure they need. We've got a Mazda 6 fitted with 225/45R17 tyres and run them at 38psi front 36 front; the tyre place recommended 38 all round. That's higher than what Mazda recommend for the 15" tyres that were fitted stock.

With my RSC I've just gone from 205/45R16 to 205/50R15 and have found running the pressures lower (30 front, 28 rear) works a lot better for maximum grip and best handling. Previously I was running 33/31.

 

[Justin]

Same pressure, but it'll just take more air if the tyre volume is bigger.