Hello,
I have a 2001 Honda civic EX coupe. I got it 2 weeks back. Previous owner has changed the regular tires and now the car has low profile N3000 205/45Z R16 tires. I do not know what psi should I keep my tires at. It says max psi 50.....

Thanks

 

Allow me to shed some light on the issue.

What carries the weight of the vehicle? Is it the tires? The wheels? Both?

The answer is, neither. The air inside the tire is what carries the load of the vehicle. Proper inflation ensure that the tires will have enough load capacity to carry the weight of the vehicle, plus people, luggage, the dog, etc.

So if you put a 19" tire on a Civic, you would ABSOLUTELY use the SAME pressure you would use on 15" or 16" tires (as long as proper plus-sizing has been utilized.)

I've used this example before, but think about a balloon being squeezed against a flat surface -- like a table. As you squeeze the balloon down against the table, the ballon's 'profile' gets shorter. Is the quantity of air inside the balloon getting smaller? No, the air chamber remains the same size.

So yeah, ALWAYS inflate your tires according to the manufacturer's specs, and NEVER by the maximum inflation pressure. Inflation fluctuates in 1.5 psi increments for every 6.2 mph, so you can quickly run out of 'room' if you set the tire at its utmost pressure capacity.

 

If read the opening correctly, then the OP got home from getting tires installed and found them at 50 psi. I did this once also. The tire place did not recommend this pressure, the installer used a fairly high pressure to seat the tires and did not check it well. I usually run manufacturer's spec, and perhaps about 2 lbs more, in front, when I use 17". There is not much tire on the rim, and I hope that a slightly high pressure protects the rim from deforming/bending on rough road. I also find that this transmits road bumps too well, and I prefer 16".

 

I usually don't have a problem with a +-2 psi tuning in certain conditions.

 

Those tires are too small for your car. Those undersized tires are 5 percent smaller in diameter than your stock size (185/65-15) so your speedometer and odometer are both registering 5 percent higher than the actual miles you are driving. You can use them up, but when you need to replace them, you should be getting size 215/50-16.

As for the tire pressure to use, Cooper is correct. Stickied at the top of this forum is a topic:

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