Tire pressure

[Omathisen]

Hi,

Starting out with 16 inch wheels on my ERA, I did not find suitable replacement tires for the street when the time came. So I got new 17 inch wheels and Goodyear Eagle FI 245/45R17 for the front and 285/40R17 for the rear. In the past I have running 24 pounds in the front and 28 in the back. But as our roads around New York are getting worse and worse, I am thinking about lowering the pressure to make the ride a little softer. It is not bothering me as much as I want to take care of the car. Anybody have any thoughts?

I have been driving this car for 16 years and it is still a blast. Went out this afternoon just to air it out a little. . .

[gsharapa]

Your tire manufacturer puts recommended tire pressure on the tire itself and I would start with that pressure for your base and then if you don't like the ride or traction lower it a bit. If you run them too low they will run hotter and of course wear the outside rims vs across the tread. I used to run 17s on a SPF years ago and I believe it was much higher than you are currently running. I'm current running Goodyear 15 inch Billboards and those are much different but still running 26 in the front and 23 in the rear.

[Grey 65]

I have a 2,450lb Backdraft that came with Goodyear F1's (although I no longer run F1's) and I run 25psi all the way around. I came to use this pressure using a tire pyrometer.
You can do like Gary said and start out with what the tire manufacturer recommends and work down from there. Do not work up as your car is lighter, not heavier than the average car that would use those tires.

My current tires BFG Rival 255/40/17 and Nitto NT05 315/35/17. BFG will not make a 17" Rival wider than 255 until late 2015.

Kevin.....

[kevins2]

You'll get a lot of different answers to this question, for sure. I would think, though, that you'd want higher pressure in the front than in the rear. ERA recommends 28 front and 26 rear as a starting point - with 15" wheels. They also state to check manufacturer's recommendations for 17" wheels and low profile tires. From there it is a matter of trial and error to find what feels and performs best for you.

[Omathisen]

Thanks for the feedback.
Dug up my old ERA documentation which recommends 24 psi in front and 27 in the rear, which is in line with what I have been doing all along.
Still waiting to hear from TireRack and Goodyear. However, considering the max pressure in these tires is 51, I do not imagine that I can go much lower than what I am already doing.
Just have to find smoother pavement.

[Jeff Frigo]

Put a set of Goodyear bias plys on it, you will never regret it except for the firt two mile when you take it out of the garage. I love mine and have heard so many people say that is a real one. I ask them why they say that and most of them say it is how the tires look. I go One step further and leave the letters dirty. I have them set to 26 front 28 rear.

Jeff

[kevins2]

I just rechecked my ERA manual to make sure I didn't reverse the numbers I stated above, and I didn't. Interesting that the tire pressures front to rear are reversed from your manual to mine.

[strictlypersonl]

I hadn't noticed that the recommended tire pressures are different in the 427 manual and the FIA manual. The correct starting pressures for both cars are 28 psi front, 26 psi rear when using 7.5" and 9.5" wide wheels. Depending on the tires, I would probably end up with somewhat less pressure after road testing.

[Omathisen]

What can I say. My 427 SC manual says start with settings (cold) of 24 psi front and 27 psi rear.
I did hear back from TireRack and Goodyear, and both in typical corporate speak said I should follow the pressure indicated on the "door placard" (I am still looking ) or the manual.
Oh well, I will just continue to do as I was doing, maybe go down one or two pounds when its gets colder and the pavement gets harder. As for switching tires, these GoodYears got a lot more miles in them.
My previous set was Goodrich tires and they were doing fine and eventually retired mostly from old age.

[motordean]

28 & 26 is perfect...a few pounds less will not kill the wear too terribly.