Tire dilemma,265's/245's/or 235's,can anyone help?

[AgmansDuramax]

Hello everyone, I am trying to decide on what tires to get for my 02 Dmax, it's the 2500 HD 4x4 with a flatbed (the one in my photo). Anyway, it has Michelin 265/75-16's on it now, that's what I bought it with, and I'm getting about 16-18 mpg, hand calculated, with just a 4" straight exhaust, no muffler or cat, everything else is bone stock. I'm wanting to get the best milage I possibly can, while I also tow a 16' gooseneck flatbed, on occasion, but not that often. I will be taking some long trips with the truck, like to Minnesota, and California, so I'm taking that into consideration as well. I am wanting to stay with the E load rating, for towing, and a semi agressive lug pattern, as I can get into some mud at my farm, but I don't really do much off roading to speak of. One option I was considering was going with a 235/85-16, which would still give me about the same tire height (as the 265's), but it is also a skinnier tire, and I'm wondering if this would have any ill effects? Also, would going back to the 245/75 be my best bet? The only mods I plan to do to this truck is putting an Air Dog II on it, to try and help my new injectors last longer, and maybe a stock tune, or possibly the EFI live with 5 way switch (IF I can swing the cost), in the effort of getting the best mpg I can. I would greatly appreciate any input you all could give me, to maybe help me decide on which way to go. I don't care how the tire "looks" on the truck, I'm strictly a "best performance/best mpg/and best bang for my buck" type of guy (I guess that's what "age" does to a person), and I will be staying with the stock rims too. Thanks in advance for your time,assistance, and consideration, I greatly appreciate it!

 

[BudTX]

Those 235s will give you less rolling resistance than the wider 275s, and may up your mpgs a little. I used to run 235/85 MTs in the winter when I lived on an often unplowed dirt road, and they were just a hair taller than the 265/75/ that I ran the rest of the year. I don't think that the 245s will be as useful as the taller 235s from an mpg standpoint.

An open exhaust and intake coupled with a good tow tune will give you the most bang for the buck.

 

[AgmansDuramax]

Thanks BudTX, I really appreciate the input, I'm trying to find the best "compromise" to fulfill all my needs, while keeping the milage in the optimum range. Your thoughts on "mods" is right in line with what I have been contemplating, thanks for reafirming that! I do have 1 other question though, are you saying a "good tow tune" would actually be better than the "stock" tune, if I'm just going with 1 tune, vs. the 5 tunes? Will that still give me good mileage when NOT towing, i.e. highway and in town driving? Thanks again!

 

[BudTX]

Yes sir. You can improve your towing performance and unladen mpgs with a good tow tune. Heck, I used to have an old Predator plug-in tuner, and got right at 22 mpgs (hand calculated) on a 2000 mile round trip to Texas several years ago using the canned 90 hp tune. A good EFI Live tune assortment from one of the good vendors here will address your needs nicely.

 

[gardnerteam]

I do a lot of towing from Oregon to Midwest and South - have had 4 D/A's and a 5th 2015 due in early May. Last two have been dually - all HD or 1 ton 4X4. Tire depends on your criteria for tire. My tire criteria is long wearing, quiet, strong casings, load range E or better, and very stable with heavy loads on snow and ice for winter driving in the NW and to the midwest along I-94 and I-90 WITHOUT HAVING TO USE CHAINS! Since 1979, my tire size of choice has been LT235/85R/16 and will be LT235/80R/17 on my 2015 which I will retire before I bring it home. Reasons for that size are 10 ply load range E, good height, but not too tall to hurt mileage, NARROWer than many, which means much more stable in snow and ice and better mpg due to less drag, lots of choice, and good mileage. About 5 years ago I tried Goodyear Wrangler Silent Pro's, and got close to over 100,000 miles on them. Bought a second set for another truck and got over 80,000. Best part was they gave me great towing mileage (I tow 24,000 to 30,000 GVCW up and down the Rockies, Cascades, and CA's Grapevine) AND they were extremely stable on snow and ice (just keep your speed down). Goodyear came out with a new version 6 months ago with Kevlar and I bought a set and went to Montana loaded with 2 cars on snow and black ice. Kept speed at 40 to 45 on the ice and they were FANTASTIC - no problem up and down (love tow haul down) and no slippage. I have a set waiting in 17" for my new truck. And one other interesting thing - about two years ago I started selling off my truck and trailer tires (ST235/85R/16 14 Ply) at 40 to 45% rubber left, and they sell quickly and for great money on Craigslist - I now have people wanting and waiting for a set. I get back about 50% the cost of the tire - I am always driving on newish tires.

 

[danzick]

I would go 235/85 for sure. tall/ narrow. less resistance and with the right tread they are awesome on icy roads.

 

[jacobdewey]

235/85 for sure. Remember that our engines are still just a big air pump, so anything to improve flow will improve economy. A good EFI Live tune from a reputable tuner goes a long way too.

 

[2003Duramaxlb7]

I've been Looking at new tires and came across this thread.. I was at a local tire store today,and asked the guy for aprice on some 235's he said.. Im not going to sell you those, there too narrow for the truck.. Plus you wont find much in that size, I said man I've read and hear that people run them on Duramax's all the time.. He looked up the size and he's like ohh there are quite a bit...
So my question is, Did you buy the 235's and how do you like them?