Buying new tires

Old school fronts, summer drives and trailer tires....goodyear 661.

 

The xza3 is a 275/80 -- it'll work fine instead of 295/75.

The G572 don't have the best rolling resistance (131) -- you could get a suitable all position tire in the 90's -- but at today's diesel prices tire wear might be more important than fuel economy...

 

Rolling resistance according to who? Independent lab or Michelin? I get excellent fuel economy out of 572 tread. Much better than the original yoko virgin tread it replaced TY577.

 

Yeah I saw those same pictures. I've always had good luck with them and will continue using them. The thing with tires is no two trucks are alike. You need to find what works for you and stick with it. I tried yoko steers 3 different times and never had any luck with them but their drive tires I liked. G399 has been good to me so it's what I'll continue to use. I have no idea on tire prices. Been a while since I bought any.

 

The TY577 has slightly worse rolling resistance (132) than the G572 fuelmax (131) according to Michelin. Bridgestone's numbers are pretty comparable...

 

My last set of G399 steers went 165k. Had I rotated them once or twice, probably would have gone close to 200k. I put on another pair a few months ago. FWIW, @rollin coal and I have about the same truck, except his is faster because it's black.

 

I'm a fuel miser -- to the point of it being more hobby than business sense. I run Wide singles (xone line energy d) -- 89.

Quick calculation: Rolling resistance is ~50% of mpg at 55mph. Drive tires account for ~42% of rolling resistance (34,000/80,000). So by going from 131 to 89 on the drives, your drive tire rolling resistance would be 68% (89/131) of what it was. That would lower your overall RR by 14% -- ((1-.68 )*.425) -- which would improve your mpg at 55mph by 7% (14/2).

If you got 7mpg before, you'd get 7.5mpg after -- saving 1,000 gallons every 100,000 miles. At $4/gal that'll almost pay for itself in a year. At $2/gal, not so much...


Anyway, I wouldn't recommend a wide single conversion now, but an all-position tire like Yokohama RY617 (RR 98 ) would improve mpg by ~ 5% compared to g572. But it has 18/32" tread instead of 30/32" -- meaning it should last 57% as long. But they cost $360 instead of $500, which combined with 5% mpg improvement should make it the more economical choice...

 

SHUNIA: 275, 285, 295 22.5's all have a very similar revolutions per mile and can run side by side. Do not make your decision based on those three numbers.