Does anyone here know how much air should be in challenge wheels with 235/40/18 fronts And 295/35/18 rears Thank U!
How much air pressure goes in a tire is dependent upon:: A) the kind of tire it is B) the aggressiveness of the driver C) some of the drivers style None of which you supplied. But there is a guaranteed way to figure all of this out. There is this device called a probe tipped tire pyrometer. After a long run at the desired level of aggressiveness, you measure the tire temperatures at 3 locations across the face of each tire. If the three numbers are co-linear then the tire pressure is correct. Co-linear means the middle reading is the average of the outside and inside readings. Every other tire pressure is wrong.
The tyre pressure is very much a compromise, not an exact science. I believe that the factory recommended 35 psi front and 38 psi rear (for 348) are to cover the speeds up to the maximum and for an average climate (heat). Some car manufacturers give two pressure settings - one for up to say 160 km/h and another for more than 160 km/h; the difference in the pressures can be as much as 4-5 psi. For track use, where the tyres are heated up much more than in normal use, you start with much lower pressure than usual (the mentioned 29 psi is about right as it will go up by 6-10 psi when track-hot). So, on a 348 for road use, I would go with some 32 front and 34 rear. If I was going to drive the car on a highway at 200 + km/h for sustained periods of time (can you do it nowadays?) then I would stick to the factory recommendation.
