Recommended tire pressure for 235/50/18 on a V-6
05-23-2011, 04:30 PM
#1
Thread Starter
Join Date: May 2011
Location: Texas
Posts: 7
Recommended tire pressure for 235/50/18 on a V-6
Wanted input on what pressure others are using for theirs. I recently replaced my stock 215/65/16 BFG with 235/50/18 Perilli's. Although max PSI is 51, I know I shouldn't be no where near that.
Can anyone tell me what is states on inside door jam of 2011 GT 5.0? (These came off that model.)
Also, I'm assuming my '09 V-6 is lighter than a 2011 GT, so wouldn't I need to compensate slightly for the weight difference, vs. what Ford recommends for tire pressure?
NOTE: I didn't have to use wheel spacers, hub-centric spacers, etc. Tires fit perfectly, and TPS is working fine. ALthough it did come on for a few hours after they were installed.
Can anyone tell me what is states on inside door jam of 2011 GT 5.0? (These came off that model.)
Also, I'm assuming my '09 V-6 is lighter than a 2011 GT, so wouldn't I need to compensate slightly for the weight difference, vs. what Ford recommends for tire pressure?
NOTE: I didn't have to use wheel spacers, hub-centric spacers, etc. Tires fit perfectly, and TPS is working fine. ALthough it did come on for a few hours after they were installed.
05-24-2011, 09:28 PM
#2
5th Gear Member
Join Date: May 2005
Location: S.burbs Chicago
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Well, pre 2011 v6 pony package came with 235/55/17 @ 35 psi, same as the GT.
And the GT that came with the 235/50/18 option was @ 35psi.
without getting out my tire books and using my brain, go with 35
And the GT that came with the 235/50/18 option was @ 35psi.
without getting out my tire books and using my brain, go with 35
05-24-2011, 11:55 PM
#3
Thread Starter
Join Date: May 2011
Location: Texas
Posts: 7
Ok great, but wouldn't it seem logical to reduce it a bit since the V-6 is lighter than the GT? Wouldn't the weight of the vehicle be a factor for the pressure? And since the pressure that Ford recommends is 35PSI, it seems that I would perhaps go a few pounds less?
05-25-2011, 12:00 AM
#5
Thread Starter
Join Date: May 2011
Location: Texas
Posts: 7
TPMS is coming on now intermintently. The bloke that I purchased these from said the TPMS took about 2 weeks to finally 'set in' on his GT. If mine doesn't come around, should I purchase one of those TPMS remotes to get it synched?
05-25-2011, 12:10 AM
#6
Thread Starter
Join Date: May 2011
Location: Texas
Posts: 7
Alllllllllll-righty then. 35 it is! Thanks very much for the input. On another note... I had a chance to see how they handled tonight in inclement weather and they were pretty good. We were dodging the tornadoes here in Dallas tonight, and I'd be damned if I was gonna leave my pony car in thre garage for any tornado to damage. Insurance only pays off my car if totaled, they don't replace. Anything over 80 and the front end didn't feel tight. FWIW...I'm taking it to Ford dealer tomorrow for alignment, as the original take-offs shown excessive wear on the both inside front tires.
Funny thing...front tires still had 5/32 tread (and inside wear) and the rears were down to 2/32 after only 7500 miles! BF Goodrich apparantly made a bad batch, or is this normal for a Mustang?
Funny thing...front tires still had 5/32 tread (and inside wear) and the rears were down to 2/32 after only 7500 miles! BF Goodrich apparantly made a bad batch, or is this normal for a Mustang?
05-25-2011, 01:09 AM
#7
4th Gear Member
Join Date: Nov 2010
Location: Indiana
Posts: 1,717
Hmm, I keep mine at 35 psi.
But about the wear- those two axles seem WAY off in terms of even tire wear. Have you been doing some burnouts or something? Lol maybe a thorough alignment check is in order, because it doesn't sound normal- even for a mustang.
But about the wear- those two axles seem WAY off in terms of even tire wear. Have you been doing some burnouts or something? Lol maybe a thorough alignment check is in order, because it doesn't sound normal- even for a mustang.
05-25-2011, 02:36 AM
#8
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Join Date: Mar 2009
Location: Houston, Texas
Posts: 1,731
but seriously glad you got through the tornadoes ok. and i would just go with 35 since almost all mustang tires run that
05-25-2011, 07:07 AM
#9
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Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
My 2008 GT Premium (coupe) calls for 32 psi in its OE 235/50-18's. The car is fairly well equipped but does not have the (heavy) Shaker 1000 or any aftermarket entertainment equipment so it isn't unusually heavy.
Your 2009 V6 should still weigh a little less than an '08 GT, probably about a hundred lbs or so. You could possibly justify running slightly less in the lighter car, but the amount of "slightly less" would only be about 1 psi less.
That 32 (or 31) is really either a starting point or a "put the blinders on and just use the setting that Ford thinks is OK for most people without thinking any further" number to hang your hat on. Keep in mind that Ford's tire pressure recommendations are based in part on maintaining an amount of understeer that's perhaps more than really necessary.
You can get a little improvement in cornering "turn-in" and a little reduction in understeer by running the front tire pressure up just a little. Too much of an increase starts making the ride harsh in the front. 34 or 35 psi here seems about right for a GT.
Ride quality and rear tire grip (for both acceleration and hard cornering) tend to improve by running slightly less pressure than Ford's spec in the rear tires, and understeer tends to be reduced a little more from this as well. As long as you don't normally carry heavy things in either the trunk or back seat, 30 or 31 psi out back will work just fine.
Even in normal driving, the cornering improvements make the car a little more responsive and maybe feel like it's a little "lighter on its feet" than it actually is.
Norm
Your 2009 V6 should still weigh a little less than an '08 GT, probably about a hundred lbs or so. You could possibly justify running slightly less in the lighter car, but the amount of "slightly less" would only be about 1 psi less.
That 32 (or 31) is really either a starting point or a "put the blinders on and just use the setting that Ford thinks is OK for most people without thinking any further" number to hang your hat on. Keep in mind that Ford's tire pressure recommendations are based in part on maintaining an amount of understeer that's perhaps more than really necessary.
You can get a little improvement in cornering "turn-in" and a little reduction in understeer by running the front tire pressure up just a little. Too much of an increase starts making the ride harsh in the front. 34 or 35 psi here seems about right for a GT.
Ride quality and rear tire grip (for both acceleration and hard cornering) tend to improve by running slightly less pressure than Ford's spec in the rear tires, and understeer tends to be reduced a little more from this as well. As long as you don't normally carry heavy things in either the trunk or back seat, 30 or 31 psi out back will work just fine.
Even in normal driving, the cornering improvements make the car a little more responsive and maybe feel like it's a little "lighter on its feet" than it actually is.
Norm
Last edited by Norm Peterson; 05-25-2011 at 07:10 AM.
05-25-2011, 01:17 PM
#10
5th Gear Member
Join Date: May 2005
Location: S.burbs Chicago
Posts: 4,793
Norm you got me thinking now, I could have swore my 06 said 35psi. I could be wrong, or Ford has changed since then. Too bad the car is not here to go check.
As far as the tire wear issue, sounds like someone was not rotating their tires on a regular basis. And some spirited driving.
As far as the tire wear issue, sounds like someone was not rotating their tires on a regular basis. And some spirited driving.