What are the correct tire pressures?
08-20-2010, 06:14 AM
#3
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
The front tire carries the same load index as the 235/50-18, so 32 would be adequate in terms of load capacity. However, you've got a much shorter sidewall, so you might want slightly more (2 or 3 psi more?) to provide a little more resistance to getting pinch flats or rim damage on sharp edged potholes and such.
The rear tire has about the same load index as the 285/40-18 as used on the 2008 GT500 (I think it differs by one). So I'd start with whatever inflation pressure that Ford spec'ed for that tire, and again add a little.
Warning: long way of asking for a little patience . . . . . 7:00 AM is about as early as it gets for me to look at any new stuff, and I'm sorry to report that I can't surf the net, read stuff, and reply to it while I'm sleeping. Hell, I refuse to "multi-task" when I'm awake.
Norm
The rear tire has about the same load index as the 285/40-18 as used on the 2008 GT500 (I think it differs by one). So I'd start with whatever inflation pressure that Ford spec'ed for that tire, and again add a little.
Warning: long way of asking for a little patience . . . . . 7:00 AM is about as early as it gets for me to look at any new stuff, and I'm sorry to report that I can't surf the net, read stuff, and reply to it while I'm sleeping. Hell, I refuse to "multi-task" when I'm awake.
Norm
Last edited by Norm Peterson; 08-20-2010 at 06:16 AM.
08-20-2010, 06:26 AM
#5
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
Norm
08-20-2010, 06:52 AM
#6
6th Gear Member
Correct in what respect? Norm has given you the technical info but you also need to balance that with what's correct for YOU and your driving needs/style. With the 20's, you've limited yourself somewhat in regards to having to maintain a slightly higher pressure to protect the rims IF that's an issue for YOU. Depending on the roads in your area, you may not want kidney damage from riding at too high a pressure.
08-20-2010, 07:19 AM
#7
4th Gear Member
Thread Starter
Join Date: Apr 2008
Location: San Diego, CA
Posts: 1,486
Excellent info guys, thanks Norm. The only reason I'm posting at that crackhead hour of the night is because my 2 month old has no concept of time??? 
20x8.5 - 35mm
20x10 - 38mm
I drive 80mph most of the time and go around corners fast.
PS. I just had this staggered setup installed and I'm not sure what the pressure is now, but it looks like 1/2 inch on either side of the rear tire is not touching the road, even under hard cornering???
20x8.5 - 35mm
20x10 - 38mm
I drive 80mph most of the time and go around corners fast.
PS. I just had this staggered setup installed and I'm not sure what the pressure is now, but it looks like 1/2 inch on either side of the rear tire is not touching the road, even under hard cornering???
Last edited by Roy_R; 08-20-2010 at 07:25 AM.
