Fuel miser

Michaelinthetwigs · September 26, 2016

Ight fellas, I've got myself a 04 1500 4x4 crew cab. The tired lm7 has been swapped for a lq9. The stock 4l60 is going to be swapped for a FLT 4l60 sometime in the near future. Stock 6.0 for now but planning on going ahead and doing a larger stall convertor for performance gains. Currently driving 1k+ miles a week. 93 ethanol yields around 17-18 throughout a full tank. 93 pure gas yields around 19 - 21 Hwy. Truck is factory 373 and g80. I'm running goodyear wranglers 265/70/17 passenger tires. Wanting the Duratracs in load E because I've read the softer C doesn't last. If I went with a 245/70r17 would they decrease my Hwy mpg? I don't care about wheel well fill. I care about my wallet. I've ran a 235, 245,265 and even the 285 series tires on my old sierra extended cab. Before someone gets excited and chimes in about a Prius I'm actually buying a 2003 jetta tdi then tuning the pcm in hopes of 60 mpg lol. Google it, it's real. Ok. So I know a all terrain won't help but want the winter capabilities and don't want 2 sets of tires. All that being said has anyone compared 265 to a 245 as far as Hwy fuel economy? Thanks, sorry no pics for attention.. I'm boring like that. On a side note I do plan on a aem/MIT tube and borla gmpp touring muffler asap... Pcm has been tuned already.

Nanotech Environmental · September 27, 2016

Id expect a 245 would not help you with fuel mileage, as they should be a bit smaller in dia. than a 265.

_level_ · September 28, 2016

How about a 255/75r17? Possible taller and narrower could help improve highway speed mileage.

intheburbs · September 28, 2016

Can't speak with certainty to the effects of different sizes/widths, but I can tell you that when I put Duratracs on my Suburban (replaced Michelin MTX or a similar Michelin road tire), the same size as the previous tires, 245-75-16, my mileage went down. The same characteristics that make the Duratracs great in snow, rain and mud, are precisely the characteristcs that reduce your gas mileage.

My guess would be that the narrower, smaller tire will probably be better on mileage than a wider larger tire. Rolling resistance of the larger tires will likely overshadow the slightly increased engine speeds you'll see with the smaller tire.

Michaelinthetwigs · September 28, 2016

Now we're thinking... I know the smaller 245/70 increases my rpms. An online gear calculator actually says my 373 transforms into a 386 or similar.. Knowing they don't offer such a gear that's what math spits out. Goodyear has height /width and even revolutions per mile. Going to a Lt tire for longevity because the Duratracs are soft I'm just curious. Hoping for user information as posted above. Lt duratrac in same size as passenger tire on my daughter's 4runner didn't affect mileage. Seeing alot of nnbs trucks on current job with 245/70r17 I like the smaller tire. It fits the NOT normal and sleeper status I desire. I wish they would improve my Hwy and also give quicker off the line results. Hmmm, keyword being wishful.