Tires & MPG
 

Have any of you noticed any better fuel mileage if you change to passenger tires rather than OEM or similar light truck tires? I do a lot of highway driving and I'm wondering if I would save some cash changing to a non light truck tire. The truck I just bought, 4x2, 2 door, has a set of Yokohama Geolanders. Thanks..

RE: Tires & MPG
 

I am using passenger tires and don't have particularly good mileage at the moment, so there may be other issues involved such as inflation and the load I've been carrying around. I had wondered the opposite question, since the Blazer had worn-out Uniroyal Laredos on it when I bought it, and the previous owners are acting like they got better mileage than I do. So I'll be curious to see other responses.

RE: Tires & MPG
 

If your tire size starts out with 'P', then you are already running a passenger rated tire. If it starts out with an 'LT', then it is a light truck tire. The weight of the rims & tires has a lot to do with the fuel mileage.

Even more influence centers around proper inflation. At a bare minimum, the tires should be inflated to the recommended rating on the door sticker. If you are highway driving, recommended or a few Psi over (so long as it is still below the max manufacturer rating on the sidewall of the tire) is where I would run it. The ratings on the door are for the best 'happy medium' between ride comfort and fuel mileage. By increasing the tire pressure (while still below the max pressure rating), you can decrease the rolling resistance, by decreasing the tread contact patch, at the expense of a stiffer ride. The tires do quite a bit of road abnormalities in combination with the springs/shocks.

In short, your tire pressure should never fall below that of the rating on the door sticker, and should never exceed the maximum rating on the sidewall of the tire. Too low of pressure can cause poor gas mileage and cause the tires to prematurely wear. Too high of pressure could cause catastrophic failure.

RE: Tires & MPG
 

I'll add a little pressure to see if there's a change at all. Thanks for the tips...

RE: Tires & MPG
 

Passenger tires don't have the sidewall strength as light truck tires. Driving with a load and passenger tires will make the truck squirrly, and it will flatten the tires out so much that your fuel mileage will go down, plus prematurely wear them out.

Light truck tires are heavier then passenger tires, and they carry the load much better. Then don't compress as much and will not get squirrely, especially while towing, nor any of the other bad characteristics of the passenger tires while under a load. The down side is the light truck tires have a stiffer ride then passenger tires. And that can be controlled by air pressure.

Personally, if this truck is a grocery getter and family crusier, get the passenger tires. However it your using it to haul stuff, tow, or go off-roading, get the light truck tires. I run my BFG KO's (light truck tires) at 42 psi. The ride is stiffer then passenger tires, however my fuel mileage is about the same. No real difference.

RE: Tires & MPG
 

Hmm........ well, maybe I got the wrong tires. I probably forgot to tell the guys in the tire shop that I'd be hauling around boxes of pottery and shelving 9 months out of the year. So they pegged me for a middle-aged grocery-shopping lady and sold me passenger tires.

Well, I just unloaded the truck until April, and will check the tire inflation ASAP. But here's the weird thing; the recommended pressure is 35 PSI and the maximum inflation listed on the tires is also 35 PSI. That makes it kind of hard to add a couple extra pounds or even to add the recommended amount without worrying about overinflating. What's up with that? All the tires I have bought in the past (cheaper ones for smaller vehicles) have had a higher max pressure than the recommended pressure for the vehicle.

RE: Tires & MPG
 

32-35 psi is fine. Even if you run up to 40 psi it wil be fine. I wouldn't go over 45 though. The higher the psi the more you will wear out the center of the thread pattern fsrt.

RE: Tires & MPG
 

Thanks for the reply. I went into the shop where I bought the tires and was told that for passenger tires being sold today, the 35 PSI max stamped on the side is pretty standard. I was also assured that the tires would not "blow up" if I were to accidentally or intentionally put in 2 or 3 extra pounds or even more. As you say, a lot of extra inflation would just wear them out faster.

We also looked at the load rating for the tires and for the vehicle and concluded that the pottery and display shelves I've been hauling around are not much to be concerned about. After all, I've hauled around the same amount of stuff, and picked up 500 lbs of clay, in much smaller and lighter Japanese station wagons. I'm pretty happy with my Blazer.

RE: Tires & MPG
 

hi everyone , ive been reading forum and have joined. i bought bfg long trail touring 235 75 15. nice tires half inch lower
then ko's but half inch wider in mid section. they r xl tires so load is 108t, they ride nice and keep truck planted on road
with no squirm. also changed radio to pioneer deh 2000mp sweet except for stock rear speakers didnt work so put in rear old
pair of radio shack lithum mini's sound great.