"BradandBrooks" <BradandBrooks@shaw.ca> wrote in message
news:gaI_e.278470$Hk.165483@pd7tw1no...
> What? Where the hell does Ford recommend 30psi? Go with what the tires
> say, 44psi, or, of course, you can always just blow a tire and die if you
> like.
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
http://www.Michelin.com/care/tip1.html ):
"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 (
http://www.michelinman.com/assets/pdfs/doc_harmony.pdf):
"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).
Regards,
Ed White
Linear Mode
