Kindly educate me if it's appropriate to use a 235/55 R17 for my infiniti i30t 2000 model. In which tire am currently using. And a preferred recommended pressure for it.

 

I believe the stock tire on your vehicle is a 255/50 R17. If the 235/55 R17 is currently on the car, they will work with a minimal increase in diameter.

Concerning pressure, for normal street driving go by the sticker inside your door.

 

I'm feeling pretty kindly educated now.

 

I've got a really stupid question about the tire pressure sticker.

I understand how that PSI can be correct for the brand and size of tires that came with the car, but how can that number be universal across all brands, sizes, and styles?

 

The number is based one averages for all brands of tires and is biased towards a soft ride.

All tires have the maximum inflation pressure molded into it. And there are a lot of differences. 30 lbs inflation(or whatever) will not give you the exact same performance/ride/wear with all brands of tires. I will be close though.

The lower the air pressure, the softer the ride. Things that also go along with lower air pressure are faster wearing out, less load carrying capability, higher likelihood for rim damage when hitting a pothole and poorer cornering performance.

But you probably don't want to run the pressure at the tire's maximum, either. You will probably think that you took your springs and shocks out.

Because front wheel drive cars have more weight on the front wheels than the rears, I run a higher pressure in the fronts than the rear. I do 35 lbs in front and 32 in the rears. The car does not have a harsh ride and the tires wear evenly from side to side.