CT4-V BW Tire Pressure

[Dirkbg]

I guess I know the answer, but I found it confusing that the tire pressure in the door jamb label says 35 psi but the manual says 44 psi. I got a nail in my rear tire and it was losing pressure slowly and had to get it repaired. But before I took it in I inflated it to 35 psi per the label, but noticed all the other tires were about 42-43 psi from delivery. I lowered all the pressures to 35 and thought it odd it was delivered with that high pressure until I just noticed the manual ratings. Reading more closely, I see the manual says pressures for high speed operation. So I guess the answer is to use 44 psi for high speed/racing, but probably best to use 35 psi for daily driving?

 

[raptor5244]

I guess I know the answer, but I found it confusing that the tire pressure in the door jamb label says 35 psi but the manual says 44 psi. I got a nail in my rear tire and it was losing pressure slowly and had to get it repaired. But before I took it in I inflated it to 35 psi per the label, but noticed all the other tires were about 42-43 psi from delivery. I lowered all the pressures to 35 and thought it odd it was delivered with that high pressure until I just noticed the manual ratings. Reading more closely, I see the manual says pressures for high speed operation. So I guess the answer is to use 44 psi for high speed/racing, but probably best to use 35 psi for daily driving?

Manufacturers typically keep the cold tire pressures pretty high to help prevent flat spots. Prior to delivery the dealer is supposed to set them to the proper levels though, which they rarely seem to do. Those higher pressures listed in the manual are supposed to be your rough target for track/spirited driving. A cold pressure of 35psi may reach low to mid 40s when warmed up depending on the ambient temps and the track. I have mine set at 35psi cold and see around 39-40psi during highway driving, so I assume if I really got on them I could get them closer to 42-44.

 

[strohw]

Run the door jam spec of 35 psi cold. If you planned on long stretches of 100+ mph I'd probably bump that up.

Track psi will be around 33 to 36 hot.

 

[1990E30]

I have mine set at 35psi cold, also. The weird thing is; the tire psi stays at around 35 or slight increase after driving for extended period of time (>30 minutes). At least, that is what the car tells me. I would think there should be increase of 4-7 psi with extended driving. Has anyone else experienced this?

 

[raptor5244]

I have mine set at 35psi cold, also. The weird thing is; the tire psi stays at around 35 or slight increase after driving for extended period of time (>30 minutes). At least, that is what the car tells me. I would think there should be increase of 4-7 psi with extended driving. Has anyone else experienced this?

It depends on multiple factors. Ambient temps, speed, wet or dry roads, sun exposure, etc.

How the temperature and weather affects tyre pressures

How do you keep your tyres at the right temperature when driving and the ambient temperature can increase and decrease it?

www.driverknowledgetests.com

 

[flipray]

I set mine at 35 psi. I read that same section too, where it says set it to 44 psi for track purposes and I kinda scratched my head on why you'd set it that high. Personally, I'd leave it to 35 psi cold even for the track. I've seen it get hot to 39-40 psi after flogging the car on some twisties. Maybe they meant that 44 psi hot would be the max pressure you'd want.

 

[jodakid69]

Attached is information from the Cadillac V-Performance Academy. Given the number of cars that they are tracking on a weekly basis, they probably have the most track miles of any user on CT4-V BW / CT-5 BW. They are also run in a hot weather climate. I added the red text based on in-class comments.