Rico
Costco has some "bogus" information, supposedly from Ford, that truck tires are not to be put on Ford Explorers. I ran into this when I wanted to get Costco to install Michelin LTX-MS tires (these are not truck tires) on my 91 Explorer a year ago, and Costco said that Ford stuff said no. Ford or someone was confused and thought the LTX-MS Michelins were the truck tires. I eventually tracked down the correct info, showed it to Costco, and got the Michelin LTX M/S installed on two wheels. Now that information is coming out about Ford explorer problems with the suspensions and Ford specifying tire pressures of 26 psig so as to reduce risk of rollovers, this Costco refusal to put the 6 ply truck tires on the Ford Explorers probably has to do with liability issues (perhaps something like Ford telling Costco not to install certain tires and saying that if they do so, Costco is liable, not Ford). By the way, the Costco guys I was talking to said they were installing light truck tires (6 ply) on Ford Explorers (this was a year ago). The situation is confusing. And Ford appears to be more interested in covering their butt than in getting out true and accurate information! But that is typical mode of operation in large corporations and is the result of their legal advice. And corporate attorneys carry a lot of weight in these type of matters. Mike in Seattle, 91 XLT 4x4