xudeck

Hey guys,

What tire pressure should I be using on my 225/45/17's and 245/45/17's? The maximum the tire allows is 44 I believe !! Tires are Nankang NS-1's !!

Kinda curious as to what to use, I am guessing it cant be the same as the stock 195/65/15's....lol !!

Help appreciated !!

RBYCC

Stay in a 30 - 35 PSI range, any higher pressure will cause wear in the tread center. I used to run 32 front and 35 rear.

xudeck

30-35....someone told me 35 to 40 should be fine.

I guess Ill go 35 just to be safe.

Thanks

Bigpete123

especially with low profile tires, I would also recommend pressures between 30and 35. It helps protect the rims and increase ride comfort.

ksing44

Luke from Tirerack, the god of tires, has always said to use the same tire pressures as recommended by the gas filler door, regardless of plus sizing. I then asked about fine tuning things based on specs from other cars that showed sportier models with bigger wheels and “slightly higher” tire pressures. He agreed that going up a few pounds would increase steering response and contribute to a sportier feel, but at the expense of comfort. Max is Max, not the recommended tire pressure! I also agree that slightly higher pressure may help to protect your wheels, considering the lower profile of the tires. Just know that the higher pressure will negatively affect comfort, just like your lower profile tires. I run soft, like Mercedes recommended, because I like the smoother ride. I don’t usually race anyone on my way to work. Going up to 32lbs does seem to give it a bit more of an edgy sporty feel, but for me it also makes the ride more harsh.

RBYCC

Keep in mind on a low profile / wide cross section high performance tire, a low pressure will seriously diminish performance as the sidewall is not so tall.
Also a low pressure will expose your rims to the potential of curb rash.

As far as "comfort", the design of a low sidewall inherently lacks comfort as it affords minimal shock absorbtion regardless of pressure.

If you want comfort you will not get it with a +1 or +2 tire/rim upgrade.

Bigpete123

true.

ksing44

I guess I should have said, "relatively low", rather than “low”. I didn't mean to imply that you should under inflate your tires. I run with my tire pressures at the lower end of the tire pressures listed on the gas filler door. I was just saying that the "recommended" pressures are based on the weight of the vehicle, more than on any specific tire or tire manufacturer. I think you will find that even the tire manufacturers tell you to refer to the car manufacturer's recommendations for tire pressure.

I have a +1 set-up and I find that to be nice compromise between comfort and performance. I run 205/55/16 tires on 16” x 7.5” ET37 AMG wheels. I have tried the higher range of tire pressures and the car does seem a bit more tossable, but I think the reality is that these cars are a bit heavy to be really tossable. If you tend to drive at or above about 100mph, then the recommendation is also to run with slightly higher pressures. I typically only go over 100mph for brief periods, so I don’t worry about that too much.