3-ply vs 4-ply tires

April 16, 2008 8:52 PM

Do I need to buy 4-ply tires? I am starting a research position that will involve lots of travel on rock/sand/gravel roads in Southern Arizona and Northern Mexico. A desert rat friend of mine says I need to upgrade my 3-ply tires to 4-ply tires to avoid repeated flats. Is he right?

I drive a 1991 Subaru Legacy all-wheel-drive wagon that has never traveled outside of the Pacific Northwest. Now, I need to make it desert-ready. The catch is that I will have a lot of highway driving to get to the dirt roads (from Oregon to Mexico), and fuel economy is a concern for me.

Any suggestions on off-road tires for my Suby or the 3-ply vs 4-ply debate would be appreciated.

posted by intoxicate to travel & transportation around Jefferson City, MO (4 answers total)

The catch is that I will have a lot of highway driving to get to the dirt roads (from Oregon to Mexico), and fuel economy is a concern for me.

Whatever fuel economy issues you will encounter are solvable by doing your tire shopping in the southwest, after your long highway drive is over.

Personally, I would be more concerned about using a 17 year old vehicle because of breakdowns than I would the flat issue. When I was doing lots of desert driving, I used 10-ply tires, but then I had a pickup and could easily get heavy-duty tires.

A cheap solution -- cheaper than four new tires, anyway -- would be to buy a used wheel and tire at a junkyard to carry as a second spare (I paid about $25 for one, when I did this the other year, but on a more common vehicle). Carry a foot- or 12 volt-powered air pump, in case you get a slow leak.
posted by Forktine at 9:21 PM on April 16, 2008

Seconding carrying two spares. I drove my truck often in the desert Southwest and one day I got a flat...no problem, put on the spare. About 1/2 a mile further down the same bumpy dirt road I got another flat. I ended up camping that night and hitching into town 50 miles away the next day to buy tires. Lesson learned: have good tires. Later on when I went to Alaska I carried two spares the whole time and never needed both of them but they were added confidence.
posted by fieldtrip at 9:37 PM on April 16, 2008

D rated 8 ply light truck tires are great for desert driving, I run them at 50 psi on the highway and down around thirty psi for the misery road. Thicker sidewalls= less blowouts from rock shards. The ride is smooth nice.
posted by hortense at 9:51 PM on April 16, 2008

Besides the second spare (and a first if you have one of those economy spares), I'd buy a plug kit and a 12v compressor. They shouldn't be considered a permenant repair (though many do) because they don't seal the plys but they can save you from needing to make a long walk. I've repaired a 1.5" inch gash in a side wall once with them. Enough till I could get a new tire fitted.

You can use the spare even if you do buy a new set of tires and you don't have to make that decision until you've actually experienced a few flats.
posted by Mitheral at 10:53 AM on April 21, 2008