Tires: Proper load range for 2003 F350 7.3L diesel crewcab, ford f 350, stock rims

Question
Barry,
I purchased a set of tires for my 2003 F-350 crewcab with a 7.3L diesel which the tire shop was well aware that I carried a 2500 pound plus cabover camper on.  I wanted to upsize the tires so I went with a LT285/75/16 Load range D upon the recommendation of the salesperson, who stated they could handle the load based on the weight rating on the tire.  The tires have worn down significantly since Feb 2007 and after about 24,500 miles (40,00 mile rating), I had the front right tire seperate on me traveling without my camper at about 60 mph in slightly windy conditions.  I luckily felt the seperation starting to take place and slowed to about 40 mph before it completely blew.  Where the tires that I was sold underrated for the load that I carry from time to time and do the LT285/75/16 require a wider rim than the stock size to wear properly and maintain proper stability.  Do I have any recourse on the tire dealer as my quarterpanel and bumper were damaged in the blowout?

Thank You,
Steve

Answer
Steve,

On every vehicle sold in the US, there is a sticker - commonly called the placard - that will list the original tire size and the proper pressure for that size.  The placard is usually located on a doorpost or in the glove box, but sometimes it is located in the trunk or on the fuel filler door.  Please check that placard, because the following is based on that being correct.

Tire Guides says that a Ford F-350 CrewCab came in a variety of configurations but Single Rear Wheels only had LT265/75R16 Load Range E's on 7" rims at 75 psi front, 80 psi rear.

That means the load carrying capacity of the original tires was 3260 # front, 3415 # rear.

An LT285/75R16 Load Range D has an allowable rim width range of 7 1/2" to 9"  and a maximum load carrying capacity of 3305 # at 65 psi.  

That means the tires you purchased should not have been mounted on the stock rims and there was a lower load carrying capacity at the rear, but was OK at the front provided 65 psi was used.

First, the tire dealer should not have mounted those tires on the rim - the rim was too narrow.

Second, the tire dealer should have told you what pressure to use - and should have indicated so in writing so you could refer to it if you forgot.  One way would have been to apply a sticker over or near the placard.  That way anyone who bought the truck would know that different tires had been appalied and that the placard pressure was no longer appropriate.

Since the tire dealer didn't do that, you did not know the tire had a lower load carrying capacity.  Did he verbally warn you that the payload capacity of the truck was reduced?  If he didn't, that is called "Failure to Warn".

If I were the dealer and I was confronted with this information, I would arrange to fix your vehicle.  However, if he balks, first tell him you are going to file suit in small claims court - and if he still balks, file suit, using this information as the basis of your suit.