I recently increased my tire pressure (from 32 psi cold to 40) to try to get better mileage. While mileage did improve, handling got really twitchy. I lowered my pressure again (to 32) this weekend because I wanted to see how much difference it really makes. The handling is much better. I'll hafta run for a while to see if the mileage that much different.

I'd be interrested in reading others' opinions. What pressure do you run, and for what conditions, and what kind of tire? Do you prefer handling over mileage?


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Tom Kenney
WORK: tomk@bearcomp.com
PLAY: tom@fluxtech.com

My truck, Sparky, is a 1992 F-150 XLT SuperCab shortbed 4x4, 302, 3.55 LS, 31"x10.5" Dunlop Radial Rovers, silver-on-black two-tone paint. MODS: K&N Filter, Rancho Steering Damper, Duraliner

Sparky's Page

 

I go for tire mileage -- ran 170,000+ miles on 3 sets of tires -- were p235/70R15 extra load version, and I ran them at 42psi (max tire) all the while.

Traded last truck at 42K -- ran at max tire pressure -- and tires were not half worn out.

New tires are LT series -- and I'm running them at 60 psi -- and the thing seems to roll forever. Only 8K on it so far, with some excessive toe-in apparent but all else is ok.

(update) found 60 to be unnecessarily hard. Now running 50/50 Front/Rear. 60 seems to be too hard even at 11,500 GVW with 5K being trailer. At 11,500 miles without a tire rotation, fronts are feather-edged -- suspect excessive toe in -- goint to shop for alignment and tire rotation.

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Y2K™

XLT SC SB 5.4L E4x4 AW-Disc, 3.73LS, Skid, 7700# HD Towing, Chrome LT-245, Steps, Captain's, 6CD, Tonneau, keyless, Toreador Red, called "Nick"

[This message has been edited by Y2K 7700 4x4 (edited 07-30-2000).]

 

I like the handling at 32 psi, which is still a couple higher than what Ford recommends (29 or so). 35 feels a little too hard, 29 to soft (too much understeer). I have the General OWL 255/70/16.

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1999 XLT S/C, 4.2 V-6, auto, 3.55 rear, dark torreador red/harvest gold, bed liner, Sony 10 disc CD, Edelbrock IAS, Superchip, Airaid FIPK. On Back Order - Steeda Rear Anti Sway Bar, polyurethane front sway bar bushings
Patiently waiting for: Infinity Reference Component front speakers
Waiting for the weekedn: Flex-a-Lite electric fan

 

Be careful about running too much pressure in you tires. It can and will cause premature tire wear in the center. Also running to little tire pressure can wear the outer edges. SO, what is the perfect tire pressure? Every tire is different, every vehicle is different, every person is different, and every climate is different. Personally I run about 32 to 33 psi all around seems to be okay, decent handling and 17mpg. Oh by the way I have the 255/70R16 Goodyear AP's. Suprisingly excellent wear so far at 32,000.

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stock 98 XL, Reg. cab,4.6, Auto, HD cooling package, 255/70R16 on styled steel wheels,3.55LS, Black with chrome grille and bumpers! MODS: custom stereo by me, building speaker box was a !@#$%. K&N air filter w/ airbox mod, a complete keyless entry system.

 

I have a question: My owners manual states to set tire pressure based on the sticker located on the door. The tires say 65 psi max when cold, I have a 1998 f250 LD 4x4. The sticker says 45 psi front and 60 psi rear...Is this really right??? The tires currently have 35 psi in them, I assume set by the dealer when doing rotations. Any help here would be appreciated...Thanks

 

98sleeper is correct about wear patterns and general psi. Door guidelines are good to follow for general use. Carrying heavier loads most of the time can require slightly more psi in rear tires; carrying no loads ever can require less (than door suggestions) in rear tires. Low tires also degenerate due to increased heat, and prolonged high/max tire psi can stretch tire carcases.

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
4-wheel disc/ABS,Chestnut/Parchment,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.