Why doesn't someone make a tire that is geared (pun intended) for economy. I switched to to 315/70-17 from the stock 265/70-17. My highway milage went up because the revs dropped (the 3.73 is now effectively a 3.43), but not as much as it could because the 315 is wider and a lower pressure (50 psi) tire.

If I could get a 265/85-17 that can take 80 psi (or even 100), then would get an mpg boost due to my revs dropping due to larger diameter & rolling resistance dropping (due to same width & higher perssure).

I think the truck would look pretty good too - stock tires look small because of the diameter, not width.

 

Plenty of choices for the 19.5" rim.
www.ricksontruck.com

MikeyB

 

Probably need 300,000 miles to break even on the $3000 it takes to get those wheels & rims.

The question is, why not make a non-commercial tire that can be used with standard rims?

 

The Dodge HD Rams in Mexico comes standard with 225/95/17s. Much narrower but taller than the 265/70/17 or the 235/80/17.
My guess it's a limited market right now for HD 17" tires other than the load range E in 70 and 80 series. And not to mention I believe our rims are only rated to 80psi max.

MikeyB

 

Toyo's new H/T tire is designed for better mpgs.

 

They do make tires intended for economy.

Check out this link:
http://www.greenseal.org/resources/r...resistance.pdf

The chart with the recomendations is at the bottom of the file.

Steven

 

A good read. Unfortunately in teh chart they compare everything from 185/70R14 to a 245/75R16. Kind of apple to oranges. It would be more meaningful if they would break up the chart in 3 or four charts & make a meaningful comparison. In the large tire category I sure would like to see a comparison between a 265/70R17 (@50 psi), a 265/70R19.5 (@110 psi, or whatever the max pres rating is), and a 315/70R17 (@ 50 psi).

Guess I have to commision my own study!

 

True, the comparison site does not compare all tires and all sizes, but it was all that I could find. What didn't surprise me was that the Michelin tires did well, especially the XPS Rib. I've had personal experience with that tire before, and it not only produced good mile per gallon figures, it lasted longer than any other tire that I have used, by a considerable margin. Of course, my usage was strictly on-road. If you are going to do your own research, contact the tire manufacturers, and inquire about rolling resistance.

Steven

 

Tire inflation pressures dont equate to mpg directly. what it does do is change the profile of the tire and that is what you notice. if you start putting higher numbers up then your tires were not inflated enough beforehand. There is a practical limit though. you dont want to be riding the center of your tread out. basically eveything is a compromise. a bike tire would be excllent width for decreased rolling/ air resitance but not so well when your trying to accelerate.