Tire Pressure

[nxski]

Hi,
I have just purchased some BF Goodrich A/T tires and they look slightly low in terms of pressure. As I see that a lot of you are using these tires would you be able to give me a guideline on appropriate tire pressure for winter driving / summer driving?
Thanks

[FalcoColumbarius]

What does it say on the side of the tyre? I drive on Yokohama 235/75R15's: The maximum tyre pressure is 50 PSI, I like 41 or 42 PSI. Good buoyancy & mileage as well as good traction ~ a happy marriage.

Falco.

[nxski]

The only number I can find is to inflate to 50psi cold (max) The reason I'm wondering is because when costco installed it they spent over an hour trying to find the appropriate tire pressure which is supposed to be listed in the manual and is also what the directions on the tire say to go by. Unfortunately I don't have the manual and the tire size is different from what is typically on the vehicle in Japan. The tire looks to be under-inflated. I am told it is within the appropriate range but that I should do my own research to figure out the exact pressure as they have never installed tires on a Delica before and the weight range they could find online was pretty large.

[tonydca]

The sidewalls might be thinner than the other tires. My Goodyear Expedition snows have a 4-ply sidewall (stamped as such on the sidewalls), and they bulge out more on the sides at 35 psi than my 5-ply summer Kumho's.

In the end, I have to trust what the sidewalls and tire pressure gauge tell me, regardless of what they look like!

[fexlboi]

Tire pressure is mainly related to tire load limits.

For example if you have a LT235/75R15 these are the specs for cold inflation pressures in relation to load rating:

35psi = 1530 lbs per tire
40psi = 1680 lbs per tire
45psi = 1825 lbs per tire
50psi = 1895 lbs per tire (C Load Rating)
55psi = 2100 lbs per tire
60psi = 2230 lbs per tire
65psi = 2335 lbs per tire (D Load Rating)

That means, if you have a D rated tire and you just pump it up to 50psi it gets automatically downgraded to a C rated tire. So you would need to weigh the weight on your front- and rear-axle to find out the optimal pressure. A front-heavy Delica would probably need a higher pressure in the front than in the back.

[nxski]

That's probably what's happening. Mine are LT 235/75R15's and the front looks a lot lower than the back. They are rated for a max load of 1895 lbs with 50psi (C load rating)

[FalcoColumbarius]

That's probably what's happening. Mine are LT 235/75R15's and the front looks a lot lower than the back. They are rated for a max load of 1895 lbs with 50psi (C load rating)

Have you corrected your torsion bars? With age the torsion bars sag, letting down the front end of the vehicle and should be cranked back up again. The general stock weight displacement between the axles is 60/40 (front to back) which is not really what I would call "front heavy". In fact the general centre of balance is located just behind the sliding door handle and just above the axles. This is so for cargo hauling purposes ~ they're pretty much 3/4 tonne wagons.

Delica Elevation.jpg (72.3 KiB) Viewed 4814 times

Falco.[/color]

[nxski]

No, I haven't had that done, I'm not sure about the previous owner. How easy is that to do? Would I be taking it in to the shop or could I do that myself. Sorry if this topic has already been covered. I'll do a double check of my tire pressure as well just in case.
Thanks for the suggestion!

[FalcoColumbarius]

It can be done by one's self but if you are not sure then I would take it to a shop that understands these machines. First name to come to mind would be CVI at Shell Road in Richmond (604)-247 0500, but that is because it's where I go ~ there are other shops. Amazing Autos, Maximum OD ~ they are both in Richmond. There are others further afield from you. Check out Dealer Feedback, Beefs, and Bouquets in the forum index.

Falco.

[jessef]

This is the document you want to read.

You have BFG AT 235/75R15 LT tires, although the goodyear pdf chat (below) applies as well :

http://www.goodyear.com/truck/pdf/edb_loads.pdf

Also some more info :

http://www.goodyear.ca/tireschool/kyt/maintainingATire/

Check Your Tire Inflation

Proper tire inflation is essential for safe driving and long tire life. It's wise to check your tires' air pressure at least once a month with an accurate tire pressure gauge. Be sure to check pressure while your tires are cold and have not been used recently. Even driving a mile will cause your tire pressure to increase and give you an inaccurate reading.

Should you experience continuous loss of inflation pressure, it could be an indication of a possible tire or wheel assembly problem. Consult your tire professional immediately if you encounter this situation.

Check Your Tire Tread

Look at the tread wear indicator bar that's molded into your tires. The bars are located at the bottoms of the tread grooves in several locations around the tire. When a tire is so worn that these bars become visibly flush with the adjacent tread ribs, it's time to replace the tire.

Goodyear suggests you check your tire tread every 5,000 Km.

Know What Certain Wear Patterns Mean

As tires wear, sometimes wear patterns emerge that can indicate problems with your vehicle or tires. If you see any of these patterns, have your tires checked by a professional Goodyear Retailer. Here are some wear patterns to watch for.

•
Wear on both edges: UNDERINFLATION
Underinflation of a tire reduces its treadlife by increasing the tread wear on its outside edges, or shoulders. It also generates excessive heat which reduces tire toughness. Finally, it reduces fuel economy through increased rolling resistance because soft tires make your vehicle work harder. Abnormal tire wear may also be caused by misalignment or mechanical problems.

•
Wear in center: OVERINFLATION
When a tire is overinflated, the center of the tread bears most of the load and wears out faster than the outside edges. Uneven wear reduces the useful life of a tire. It could also be the result of misalignment or mechanical problems.

•
Cups or dips in the tread: WORN PARTS
Cupping (also called dipping) is most common on front tires, although rear tires can cup as well. It may be a sign that wheels are out of balance or that suspension or steering system parts are worn out.

•
Sawtooth edges: MISALIGNMENT
If the edges of your tire tread take on a sawtooth or feathered appearance, it's because of erratic scrubbing against the road. The solution is an alignment correction.

Tire Balancing

If your tires are unbalanced, you'll notice vibration. This can lead to driver fatigue, premature or irregular tire wear and unnecessary wear to your vehicle's suspension. Your tires should be balanced when they are mounted on wheels for the first time or when they are remounted after repair. Check your tire balance at the first sign of vibration or shimmy.

Vehicle Alignment

Your vehicle is properly aligned when all of its suspension and steering components are working smoothly and when its tire and wheel assemblies are running straight and true. If you notice uneven tread wear, it could be due to a misalignment and your vehicle should be serviced by a professional.

Tire Rotation

While many people are knowledgeable enough to rotate their own tires, the procedure is especially quick and easy for a professional. Your vehicle's owner's manual will specify the proper rotation pattern and schedule for your vehicle. If no specific schedule is indicated, a good rule of thumb is to rotate your tires every 10,000 to 13,000 Km.

Tire Repair

Tire repairs should be made by a trained tire professional. Proper repair procedure includes dismounting the tire from the wheel. This allows for thorough inspection of the tire for damage, as well as the use of a patch and plug to repair any punctures that fall within the guidelines for repair.