I had Cooper Discoverer ATR's 215/86R16 that were very used...even had steel belt showing. I would not recommend those tires however. After some recent mods, I was getting close to 20mpg on the highway unloaded.

I just put on Yokohama Geolander AT/S 235/85R16. I have plenty of room between the rears, even with 50 psi. I've noticed a lot of maybe tread squirm, and the rear constantly fish tails in the ruts on the highway. It's very unnerving, and I'm worried about what will happen when it gets icy. I have about 1000 miles on the tires, and have even pulled an 8000 boat a couple hundred miles. My mileage has dropped to 14 unloaded on the highway, and 10 pulling that boat. I expected a little drop, but not that much.

Your odometer will be off since the titres are taller / this will show less milage traveled / you should get your speedo re calibrated for the different size that will help your calculations in MPG. If the tires are taller you will show (example) 55 MPH when actually you are going 60 MPH. Just my thoughts. Some where you can find out the tire difference and the speed difference, but if you have a GPS it will show you your actual speed. (mine does any how)

because you went up in size on your tires, you lowered the rpm in which you run your truck...example....on stock tires if you cruised on the freeway at 2.5k rpm....you would now be lower...like around 2....this makes your engine lug down, and actually heat up too. it is very inefficient on fuel mileage as well. you should regear back to stock to gain your mileage back

I am on my 2nd set of discoverer ATR's in a 315 70 17, and love them...i goto ver 60k on the last set of 50k atr's i had...no bad wear at all

The ATR's weared very evenly...they just didn't do well in snow. I did pull my 5ver from Alaska to Florida and back on them. I got a lot of flat tires running them as well.

I didn't think that small size difference would make that big of difference.

we ran yoko's on all our s10 blazer and loved them.

tried a set on my 2500 and took them back within a week because of the conditons you described,,,, scary as all heck towing with them

dont know if its still the case, but yoko took the tires back 100% back then within 30 days, dont know what your timeframe is, but worth checking out

I don't thing it has anything to do with size. I just put geolanders on the wifes tahoe and dropped 3-4 mpg over the exact size bridgestones. I do admit the ride is hands down better on the yoks.

your speedo is off 4.4%.so basically every 100 miles you go you actually went 104.4. Or if your speedo says 60 mph you are really doing 62.6mph.That will throw mileage off appx 1 mpg per tankful.How is tread design compared to original.is it softer compound;ie stickier which will increase rolling resistance.

Don't know if the tread pattern is much different but that makes a real big difference in rolling resistance. Going from a rib pattern to a light M/S caused a loss of 2 mpg in my old 89 gasser. Rubber compound makes a difference also. I could get nearly as good of milage as a rib pattern with Michelin M/S, but they cost nearly twice as much.

I don't care much about ride quality, as long as it's safe. I just wanted a tire I could run year round that did better in the snow. I don't drive my truck much anymore so I guess I could deal with the mpg loss.

Will the mileage get better with a programmer?

Same opinion of the Geos on my 2500hd. Very squirrelly towing (and not). They are not for a heavy vehicle.

I have a 2002 gmc 3500 dually. it's my first dually and was wondering what kind of tires do i need? is there a certain ply to look for? thanks.

You need stiff sidewalls. I am running BFG TA commericials and they are very good. I ran Kellys on the rear of the 01 dually and the rear was squirming back and forth. It was tough to tow with.
chevman:driver::driver:

Thanks for the info. I will keep that in mind when the time comes.