F-250 pulling a Hart 3-horse LQ trailer. 11' short wall. Tires are brand new 265/75/R16 Load range E. Max pressure is 80 lbs.

The sticker inside my truck door says 70 pounds in the rear tires, 55 in the front. But, with a heavy trailer, I thought about 75 in the rear tires.

Any thoughts on this?

My thoughts...

Fully loaded, your trailer is a heavy load for a 250. The tire max load capacity is calculated and tested at max pressure.

Watch your tire wear pattern. If the edges are wearing faster than the center, increase to the max 80 psi pressure.

Okay. You and I are thinking alike. Here's "the rest of the story."

We did have the rear tires at 80 psi for our weekend trip to Missouri. On the return trip home we blew the tread off the rear left tire. The trailer handled well and we got off the highway safely. Had a bit of damage to the truck around the wheel well, though! And, it's no fun, not to mention expensive, to have to buy new tires on Memorial Day away from home. Some very nice folks made the ordeal go as smoothly as possible.

But, I wondered if I should have not had the tires at max pressure. The tire guy where I bought the new tires suggested the 75 psi, saying the temperature under load would be pretty hot, thereby raising the psi. Made sense to me and I wondered if I had contributed to the tire failure by inflating to the max pressure.

I would disagree with your tire guy.

The reason for losing the tread is heat build-up. Under a heavy load the tire flexes. As the rubber flexes, the hysteresis produces heat. The heat destroys the bond between the tread and the casing. Less pressure allows more flexing and thus more heat. IF tire failure was over pressure caused by heating... Then an underinflated tire would build pressure to proper inflation pressure. By experiance we know that an underinflated tire is more likely to blow than a properly inflated tire. (The issues with the Ford Explorer tires were caused by Ford specifying a lower pressure for ride comfort than Firestone recommended)

I would further suggest that your tires are overloaded with the trailer. The only way to tell is to scale the rear axle with your loaded trailer hitched. I'll bet a dollar to a doughnut that your load is over the max tire load stamped on the sidewall. If these two questions are "yes"

... is your tire gauge accurate? and did you inflate cold tires?

Okay, you've given me a good lead. Now I need to find some scales and weigh the rig. You mention to scale the rear axle only. Not real sure how to do that. Perhaps the guy at the scale can assist me.

Suppose I find that the tires are overloaded. What then? Adding the SuperSprings is going to improve handling, but will have no effect on the weight. Would this automatically mean I should go to a dually? What about a one-ton with SRW? Do they have a higher weight handling ability?

Actually, I didn't mean to weigh the rear axle only...
Since you're going to the trouble of loading up your rig, you'll want the complete weighing.
1. front tires only.
2. front & rear tires. (subtract front tire weight from #2 gives rear axle loading
3. truck & trailer. This total is your Combined gross vehicle weight. Check it against your truck's specs.

The best solution is going to be your choice. You could:
Reduce the hitch weight by leaving stuff at home... don't fill the water tanks,
Redistribute the trailer contents.
Change the tires to a higher load range. (I don't like this method since nothing else is changed. Like wheels, axles, springs, bearings etc.

The one ton Single Rear Wheel SRW is only a tarted up 3/4 truck in my opinion. Only a dual rear wheel truck is capable of the heavy hitch weights.
Don't trust my word on this ... look up the gvwr of the two trucks of whatever brand of your choice. Just compare similar cab & bed lengths.

GM's 2500 HD is 9200 lbs a (Sarcastically) whooping 600 pounds over their 2500's 8600 lbs! Only the 3500 dually is cabable of 11,400 pounds.

I took the rig to the scales this morning. Here are the results.

With the trailer on the truck:
1)Front truck axle only - 4,120#
2)Both truck axles - 10,460#
3)Entire rig, including trailer - 20,320#

Truck on scale, trailer NOT on truck - 6,840#

I had the horses in the trailer. Pretty much just like I was going out on a trail ride.

quote:

Originally posted by NoBite:
I took the rig to the scales this morning. Here are the results.

With the trailer on the truck:
1)Front truck axle only - 4,120#
2)Both truck axles - 10,460#
3)Entire rig, including trailer - 20,320#

Truck on scale, trailer NOT on truck - 6,840#

I had the horses in the trailer. Pretty much just like I was going out on a trail ride.

10,460# - 4,120# = 6340# pounds on your rear axle. divide by 2 (two tires) = 3170 per tire. Compare 3170 to the max load stamped on the sidewall of the tire. ( I looked at the tirerack.com site, load range E tires are 3415 pounds) You're at 93% Not a lot of load margin in my mind. You need to keep the tires aired exactly to the max pressure and consider your speed / road temperature.

Did you have your LQ tanks full? Water @ 8.3# per gallon adds very quickly. 50 gallons is 415#
Plus a week-end trip means food, clothes, hay, camping gear, 1/2 cord of firewood! and other stuff...


Other Interesting info ...10,460# - 6,840# = 3620# of hitch weight. Keep your hitch clean and greased. Otherwise the ball /socket will wear quickly and get loose.

"Entire rig, including trailer - 20,320#" Looking at the Ford specs for a 2003 F250 The max GCWR is 20,000# diesel and 17,000# for the gas v10 3.73 axle. You're at the very edge in the best circumstances. Be careful driving and religious about maintenance!

Here's where I got the specs >> http://www.meadowlandford.com/2003%20towing%20guide.pdf

Thanks for posting the weights. It's interesting to see real data.

PS ... I owe you a buck since the measured load is only 93% of the max load stamped on the tire.

... unless you're gonna admit to having a lot of extra stuff on your camping trip that didn't make it to the scale lol...

Whew! Lots of information at that link you provided. But, let me cut to the chase a little bit, at the risk of overlooking something important.

Say I was to move up to a F-350, auto trans, 7.3 ps crew cab or extra cab. It appears my CGVR would still be only 20,000#. I'm going to exceed that by at least 320# (or a bit more if I admit to the little extras you suggested! LOL!) So, am I STILL not good to go??

If you mean a F350 dually, not the SRW version, then I would suggest you'll be okay. Your rear tires will be well within their load range with your trailer. The GCWR of 20,000# is only exceeded by say 500 # That's a small percentage... 2.5%

The GCWR is determined by brakes, traction and engine/transmission/axle selection. You could pull a house at 500,000 pounds but you couldn't get it to acceptable; highway speed, steer it, or stop it from 55 mph.

The only downside is acceleration and braking of your trailer. Everything will be slower. Slower to get to speed, slower up hills, slower to stop.

One other point. The GCWR includes the truck. If you have a lighter truck. say regular cab... Then you have more of the 20,000# limit to apply to the trailer.

What model year is your truck? I just randomly choose 2003. Some model years are different. Getting the ford tow guide for your year is important for accurate info.

Gee... I'm doing it again ... a second thought.
There is an important issue that's not addressed in the tow guide. That is clearance between the bottom of the GN and the top of the bed / tailgate. Some of the new trucks are so tall the trailer has to look like its going uphill when going downhill. You want the trailer to travel about level to avoid overloading the rear axle of the trailer. It wasn't so important years ago, when the linked spring axles were popular. The torsion axles used on most horse trailers today are independantly loaded.

The whole point is a dually will not squat under your trailer as the 250 you have now does.

Okay, getting closer!

My current F-250 is a 2000 model. The F-350 I will be seeking will be a dually. In the F-250's we have one choice of rear ends: 3.73. Can we get a 4.10 rear end in an F-350 vintage 2001-2003?

Look here >> https://www.fleet.ford.com/showroom/rv_trailer_towing/2...2002_SD_F250_350.pdf

On the bottom of the last page, it looks like the 4.3 axle for the V10 or the 4.10 for the turbo diesel is available.

Good stuff! It is also interesting to note that the towing capacity decreases slightly going from a regular cab to extended to crew. I'm guessing that is because the weight of the tow vehicle increases.

I am curious as to why both rear end options have the identical towing capacity. I would have thought lower gears would increase towing capacity, but I must be confused.