Tire Pressure

scraze66 · Jan 5, 2024

The sticker on the door jam calls for 30 PSI or 220 KPA. 220 KPA converted to PSI is 32. I filled my tires to 220 KPA and the ride was unbearable. I went back down to 200 KPA (30 PSI) and she rode great.

I do have aftermarket wheels which are one inch bigger than factory (20/21) but the ride is relatively the same at 30 PSI. I’m scared of the pressure being too low and possibly bending a wheel.

Is 30 PSI OK?

KTJF · Jan 5, 2024

I have stock wheels so slight difference there with a bit more sidewall compared to larger wheels.

Car was delivered at 36psi by dealer and drove fine. I adjusted them to 30psi and couldn’t really tell the difference in ride quality (noise and handling). It was during break in so I really wasn’t pushing any boundaries.

Most cars a 6psi difference would have be really noticeable. My 2cents is mag ride is so good at reacting to the road that it smooths out some of the harshness from over inflated tires.

Afterimage · Jan 5, 2024

200 kPa is 29 psi. 207 kPa would be 30psi. Try 31psi 214 kPa and see how that feels.

7 kPa = 1 psi

Murray20c8 · Jan 5, 2024

I can't believe you can tell the difference!
But the difference will mean nothing in the long run. Go with 30.

DenisC8 · Jan 5, 2024

scraze66 said:
The sticker on the door jam calls for 30 PSI or 220 KPA. 220 KPA converted to PSI is 32. I filled my tires to 220 KPA and the ride was unbearable. I went back down to 200 KPA (30 PSI) and she rode great.

I do have aftermarket wheels which are one inch bigger than factory (20/21) but the ride is relatively the same at 30 PSI. I’m scared of the pressure being too low and possibly bending a wheel.

Is 30 PSI OK?

If you are running aftermarket rim and tire sizes then oem recommend tire pressures in the door jam are no longer valid.

Difference in tire pressures will change performance characteristics of the vehicle and wear characteristics of the tires

Murray20c8 · Jan 5, 2024

DenisC8 said:
If you are running aftermarket rim and tire sizes then oem recommend tire pressures in the door jam are no longer valid.

Difference in tire pressures will change performance characteristics of the vehicle and wear characteristics of the tires

Agreed, but the difference is less than 10%.

scraze66 · Jan 5, 2024

Afterimage said:
200 kPa is 29 psi. 207 kPa would be 30psi. Try 31psi 214 kPa and see how that feels.

7 kPa = 1 psi

Thanks. I wonder why the door jam tire sticker says 220 kPa when it should be 207.

I adjusted mine to 30.6 all around and will see how that is. I am running Michelin Pilot 4S 245/30/20 and 325/25/21.

butsy · Jan 5, 2024

scraze66 said:
The sticker on the door jam calls for 30 PSI or 220 KPA. 220 KPA converted to PSI is 32. I filled my tires to 220 KPA and the ride was unbearable. I went back down to 200 KPA (30 PSI) and she rode great.

I do have aftermarket wheels which are one inch bigger than factory (20/21) but the ride is relatively the same at 30 PSI. I’m scared of the pressure being too low and possibly bending a wheel.

Is 30 PSI OK?

the sticker on the door jam is irrelevant once you put a different size tire on. The place you bought the tires should be telling you what to keep your new tires at I would think....

meyerweb · Jan 6, 2024

Interesting. I never noticed the psi and kpa pressures didn't map. With bigger rims and rubber bands for tires, I'd be inclined to go with 32 psi just to try to protect the tims.

1st Vette · Jan 6, 2024

meyerweb said:
Interesting. I never noticed the psi and kpa pressures didn't map. With bigger rims and rubber bands for tires, I'd be inclined to go with 32 psi just to try to protect the tims.

Don’t want to spill that double double !

Tire Pressure

scraze66

KTJF

Afterimage

Murray20c8

Forum counter terrorist

DenisC8

Murray20c8

Forum counter terrorist

scraze66

butsy

meyerweb

1st Vette

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