Well, I think I know what our towing problem is!

DiskDoctr wrote:

ah64id wrote:
It sounds like you took the truck in without a load, 75-80 psi is WAY too much air pressure.

Your sig doesn't say much, other than it's a F-250 XL. Is it 2/4 wheel drive? Diesel? Cab size? Bed length?

I cannot imagine you needing much more than 65 psi in the front, if it's a diesel.

The rears probably only need to be 40-45 psi unless you are towing.

New tires will squirm (my LRG's I have on now have been the worst of any tire, and where broke-in within 200 miles), having them over inflated will make the issue worse and make it last longer as tires need heat cycles to break-in and overinflated tires don't heat up as much.

I would let some air out, and drive it. If that doesn't fix it then talk to the place that sold you the tires. I would also have your aliment checked, but it sounds to me like a combo of new tires and too much air.

Just because they are rated for 80 psi doesn't mean you run them at 80 psi, over inflating tires effects ride, handling, wear, and increases puncture susceptibility.



To the people responding, read the sig. It's an F-250, they DO NOT come with P rated tires from the factory they come with E rated tires..

If you have 3 tires in 265/70R17 a LRB(P), LRD, LRE they ALL carry the same weight at 35 psi. The LRD and LRE carry the same weight at 65 psi.

This is from Toyo, other brands will be very similar.

http://toyotires.com/tires-101/load-and-inflation-tables

For reference the curb weight of a 2008 F-250 CC LB 4x4 Diesel is 7635, front 4756, and rear 2879. Lets assume some people, normal emergency items and gear. 4850/3100. That breaks down to 2425/tire on the front and 1550/tire on the rear. Now reference that Toyo chart.

The front's should be inflated to about 47 psi, so round up to 50. No more air is needed, maybe 55-60 if your going to do a long drive at 70-80 mph.

The rears are actually under the min load at 35 psi, so 35 psi is plenty for 1550 lbs/tire. I would run about 40 for high speed driving.

If the F-250 is gas, or smaller cab/bed, etc then those pressures will be lower.

Very DANGEROUS post there! :E

Unfortunately, you have read a chart and drawn ridiculous conclusions from it! Recommending 40-45psi for a tire rated for max inflation of 80psi is irresponsible and dangerous.

Running a tire at 50% (!) of its rated inflation is asking for trouble. It is grossly underinflated and is unsafe for ANY load or highway speeds!

The PROPER interpretation of the table is, "Higher rated tires (E vs D vs C) are capable of higher load ratings ONLY when inflated to the higher psi as indicated on the sidewalls of the tire. Underinflation will significantly reduce the load capacity of the tire."

Read the charts, read the safety bulletins, etc. Generally speaking, if you inflate your tires under load to within 10% of the max inflation pressure listed on the side of the tire, the tire will perform as designed.

That's sort of the point of tires with higher load ratings having higher pressures. :S

BTW, I never claimed OP was running P rated tires, that was the example I had to offer...in real life...not some crazy 'inflate to 50% of max inflation psi' nonsense :R

To the OP- unfortunately, these kinds of irresponsible and ridiculous posts come out once in a while. It makes us cringe. The only reason we respond to such garbage is in an attempt to protect other readers from severely underinflating their tires and having accidents or blowouts.

In my book, it's akin to instructing people to 'pressurize your fuel tank using hot air heated by a flame' :R

Thanks. Now I have another bald spot :D

DiskDoctr wrote:

Chock Full o' Nuts wrote:


Your sig doesn't say much, other than it's a F-250 XL. Is it 2/4 wheel drive? Diesel? Cab size? Bed length?


2WD, Gas, Crew Cab, loooong

Thanks, guys. I knew you'd come through for me. I drove it unloaded because I was going to work. Not sure they'd approve of me dragging the Whaleboat to work, even if I could get into the parking deck.

I'll tell DH to try leaking the air out and see how it drives. He wants to take it up to the lake in about 2 weeks, which is only about a 25 min drive. I'll already getting anxious about it--it really is that wonky. If it's gonna take 1000 miles or more to break these babies in, it's gonna be a problem. I cannot drive this tank into Atlanta and all points N-S-E-W as I do home visits all over the state of Georgia. I don't even want my kids to ride in the truck.

Sure, you can try a little less pressure when empty, but for pete's sake, DO NOT UNDERFLATE TO 50%! Be smart. Find what works for your truck, but do not go outside the safe values ;)

Another idea- try putting some weight in the bed and see if it stabilizes the ride. Maybe 500-1000lbs? A little load may balance your truck and allow its suspension to do its job.