"Tire Guy" wrote in news:45OdnXgrrdp snipped-for-privacy@adelphia.com:
ARE you SURE the Ford listing is MAX tire pressure? There's a big difference.
The Tire listing means exactly that. The tiremaker knows the design limits of the tire.. but he has no idea for certain what vehicle it might be used on.
The Car Mfr recommends the best pressure for load, economy/wear and handling. And has NO way of knowing what aftermarket tire MAX might be.
HOWEVER - as you may know, different tire designs may handle differently and work/ride/wear better at slightly higher or lower pressure so it should be used as a general guide.
Ford designed the automobile, therefore they know what pressure is required (they depend on quality tires, unlike the Firestones a few years ago). The max pressure listed on the tire is just that - the maximum psi that can safely be used. The tire manufacturer does not care about the handling or ride comfort. Go with the Ford recommendation.
This is a terrible recommendation. Assuming the new tires are of the same size and load rating as were supplied on the car, you should follow the vehicle manufacturer's recommendation. Michelin has the following to say (see
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): "Recommended Pressure
"Always inflate your tires to the recommended pressure listed by your vehicle's manufacturer. This information can be found in the owner's manual and often on a placard located in the vehicle's door jamb, inside the fuel hatch, or on the glove compartment door."
This is a recommendation for US drivers. P Series tires with a 44 psi recommendation are not rated to carry a higher load than other P series tires of the same size with the same load rating which may only have a 35 psi maximum pressure rating . The higher maximum pressure is to allow vehicle manufacturers to recommend higher pressures for higher speeds. The spec sheet for Harmony tires includes the following additional recommendation
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"For high-speed driving, additional inflation pressure and possibly reduced tire loading and/or upsizing is required. In the absence of specific recommendations by the vehicle manufacturer, use the following guidelines based on those in the European Tyre and Rim Technical Organization Standards Manual.
For speeds over 160 km/h (100 mph), load and inflation must be adjusted according to the table below. S-Speed Rated Sizes: Maximum Speed (mph) 100 106 112 Inflation Increase (psi) 0.0 1.0 2.0 Load Capacity (% of max.) 100 100 100 T-Speed Rated Sizes: Maximum Speed (mph) 100 106 112 118 Inflation Increase (psi) 0.0 1.0 2.0 3.0 Load Capacity (% of max.) 100 100 100 100
Of course, since US speed limits are much less than 100 mph, these recommendation in theory only apply to certain European countries (Germany).
Tire Pressure Group: alt.autos.ford Date: Wed, Sep 28, 2005, 3:11pm From: snipped-for-privacy@guy.org (Tire=A0Guy) I just put a new set of Michelin Harmonies on my 2004 Taurus. The tires have a max PSI of 44 listed on the sidewall. Ford recommends a max PSI of 30 for tires on this car. How much pressure should I use in practice? Car typically doesn't haul any heavy loads. TIA
tires get hot and pressure raises. you dont want to put 44psi in a cold tire then drive it and have the pressure raise to 55psi. on the door it will say what is recomended, use that. then you can play with it alittle to get the comfort you want (+-3-5psi)
What? ARe you saying to run a 44psi tire on 30psi? BLOWOUT ahead! Like I asked, WHERE has Ford said A taurus must run 30psi? Maybe on the stock tires... are these stock? I doubt it.
So, you are saying Ford put a 44psi tire on a car that they recommend run
30psi? (Does this car have a 60mph limiter on it?)
Are you guys crazy? Do you know what happens to severely underinflated tires at highway speed. Try it for a while. PS: wear your seatbelt, you're going to need it.
Again, would someone show me WHERE does Ford say to put 30psi in a 44psi tire? Please, explain. The original poster has no idea what he is talking about, and neither do you guys. No offence.
Tires do not increase 14psi in hot weather, so run 30 in a 44. Holy, this news group is insane. And you people offer advice? On a 44psi tire, I would run 41 to 42 psi year round. 2 to 3 psi increase is about what you can expect in hot weather. Maybe 5 max if it is really hot.
Again, would someone show me WHERE does Ford say to put 30psi in a 44psi tire? Please, explain. The original poster has no idea what he is talking about, and neither do you guys. No offence. Brad
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