Tire pressure (for 12Ounce)

12 Ounce,

I think I have read in some of your posts that you keep your tire pressure at 40PSI (or so) which of course is about 10 pounds more than the recommendation on the door. If this is true I would expect the following:

1) Increased gas milage - due to less rolling resistance.
2) Less tire wear - due to less heat generated due to less rolling resistance.
3) Rougher ride - more dense air thus less cushion.
4) Increased Front End wear - due to less air cushion of the road.
5) Decreased traction - Due to less rolling resistance.

Of course these are just my initial thoughts. Now that I have become a bit more interested in my tires I was wondering if any of the above tend to be true in your experience.

Thanks

All the above should be correct in theory and makes sense as being true. Less tire wear may not be correct as deflection of the tires radius will not be running true and your taking a big chance of say ...hitting a curb etc. and blowing a side wall out as being overly pressurized. The aluminum rims are notorise for being a tougher flat tire repair as sealant has to be used and leaking can occur by slightly dinging the aluminumrim/bead edge. Road noise would be and is, considerably higher and maxing at a recommended MAX pressure without a fully loaded vehicle (camping gear extra occupants etc. ) is a unsafe practice. I keep mine at the maximum rating at all times but watch for tires that came with the Windstar as mine were rated at max. 44lbs. ?? seems awfully high but I keep them at the recommended rating and drive safe!

I'm no 12oz :grinno: , but the manufacturer has some degree of safety factor built into the figure they list for tire pressure on the door label, but if you are running stock sized tires, you should follow the door jamb label. If not for yourself, but for the saftey of others on the road. 5psig either way probably doen't spell certain disaster, but 40psig+ will eventually cup the tires. It's amazing how many shops/tire shops/people fill the tire to what it says on the sidewall :uhoh:!!!
G/luck
Joel

DRW
I think your list is pretty much dead on. You might add:
6) More stability in turns.

But I'm almost sorry I mentioned my "experiment" with the tire pressures. I certainly hope no one would blindly follow my practices ... especially when I caution that I am not recommending them.

Though I do think the auto manufacturers have (remember the Firestone fiasco) recommended air pressures on the low side to improve the "ride" of the vehicle.... I feel that you can usually follow their recommendation for best overall results. (But, if you read the print on the sidewall of the tire, it leads you to believe that the rated load capacity of the tire is at/near the posted max pressure. ?????)

The higher tire pressure seems to work for me ... but I quickly lower the pressure if headed for snow country, to regain the tire "footprint".

Other ongoing not-recommended experiments:
Mobil 1 ATF in the tranny.
5-50w synthetic in engine.

I think I have read in some of your posts that you keep your tire pressure at 40PSI (or so) which of course is about 10 pounds more than the recommendation on the door.

I thought my 2000 lists 35psi as the recommended tire pressure on the door jamb so his 99 should only be 5psi over.

I thought my 2000 lists 35psi as the recommended tire pressure on the door jamb so his 99 should only be 5psi over.
Yep, My 2001 lists 35psig all the way around.

Joel

Yes it is 35..................

Odd when I had the tires put on they filled out a sheet that said they torqued the wheels to 100 Ft/lbs (I think it should be 90 ) and 32 PSI for the tire pressure. I don't know where the 32 came from.

Don't worry 12Ounce you have always stated that these are not a recommendation from you but merely what you have done. It is a good point though and that is we all need to decide what is right for ourselves. I like to research by asking questions before I make a decision.

I was curious as to your "experimental data" only.

Thanks

By The way this forum has been proving to be a good alternative now that Cartrakers seems to be gone forever. Too bad about all of that data on the site. It is still searchable (as of 2 days ago) I wonder how long it will last.