Real world MPG/experiences

[badm0t0rfinger]

I built one awhile back and I think you can get a 4.3 or thereabouts. Good for hauling a load and 37s I think.

Oh man 4.30 would be a good one. I had 4.27 gears (if I recall correctly) in my D2 and they worked so well. Not as much gearing at 4.56 but worlds better than the stock 3.55.

 

[Grassland]

If it helps, our heap (2011 6.2 superduty) rolling at 10,000lbs with a big camper & 35's has been averaging 9-10MPG
over the course of the last 10k miles, nearly all of which are North Idaho miles, so little to no flat stuff.

I think that's pretty damn reasonable

 

[billiebob]

I drive a TJR I've had stock 245/75R16s, 255/85R16s, 35/12.50R16s. 33/10.50R16s, now 7.50R16s... technically a 32/7.50R16s.

Real world, every bigger tire incrimently chiseled away at my real world MPG. I never paid attention. I just hated the 35s cuz they were the most uncomfortable, worst performing, maybe even unsafest tires for a Wrangler. Going to 33s was a light years improvement. But on MPG, going from 33s to 7.50R16s gained 5mpg. with a 19 gallon tank that adds 95 miles to my range.... theoretically. Real world, yeah that change to pizza cutters adds 95 miles to my highway range.

I could never do Revelstoke to Calgary without stopping for gas.... well maybe if I ignored the low fuel light.... maybe. But now, Revelstoke to Calgary,,, I get there and park in North Calgary and the low fuel light is still off. Even better the ride is better. Rolling resistance is soo much lower I found myself needing to hammer the brakes at red lights I used to coast up to with the 33s.

Real world, you want more range, better MPG, get tall skinny pizza cutters.



I now have these tires on my SquareDrop Trailer too. 1 spare for the jeep and the trailer OR 3 spares for the Jeep if I ever get stupid.

I hear 7.50R16s are the most common tire size in Africa,,,, if you ever go there.
Before the 235/85R16, they were the common tire here too.

 

[Todd780]

If they put the 10 speed behind the 6.2...it would probably never have to rev over 2500 RPMs....haha.

That would be brilliant and perfect for me.

 

[ricoisme26]

If it helps, our heap (2011 6.2 superduty) rolling at 10,000lbs with a big camper & 35's has been averaging 9-10MPG
over the course of the last 10k miles, nearly all of which are North Idaho miles, so little to no flat stuff.

I think that's pretty damn reasonable

I'd say its very reasonable for driving a house around hahaha

but that looks like a seriously sweet set up you have there @IdaSHO

 

[Deleted member 9101]

That would be brilliant and perfect for me.

Same here, if I was to ever need one.

 

[rruff]

Real world, you want more range, better MPG, get tall skinny pizza cutters.

I don't believe that is universally the case. At least in my research and personal experience it isn't. I was surprised to learn that wider tires with shorter sidewalls actually trend towards improved MPG, which is one reason why car tires have gone in this direction over the years. It's a small effect though.

The biggest variable is tire design. A tire of any size with thick chunky tread and durable sidewalls will have relatively high rolling resistance. You need a tall sidewall on an offroad tire regardless, and wide tires with the same design are substantially heavier, which has negative effects on suspension performance, and a slight effect on acceleration (less than most believe). There is also a lot of variability in materials and construction between makes and models. People tend to believe that tires in the same category will have similar rolling resistance, but this isn't the case. The tread compound and sidewall design make a big difference. But it's damn hard to tell which ones are good and which aren't due to lack of testing.

My truck came with 255/70r18 Bridgestones with street tread. I replaced them with 325/65r18 Hankook ATMs. I was hoping to find something decent in the mpg department and based on anecdotal reports and one test I found on a different Hankook truck tire, I thought these were a good bet. I was surprised though that mpgs actually *improved*. At 75 mph it seems to be slightly less, but most of my driving is at slower speeds. It's hard to be certain because "just driving" doesn't control for important variables, but I think it's safe to say they are no worse overall. Which is pretty amazing when you compare the two tires side by side.

Another big factor at highway speeds is how the aero drag is effected. A larger diameter tire will lift the truck, screwing up all the effort the of manufacturer to design an aero front end. A lift will make it even worse. Same for tires sticking out past the wheelwell.

Also, taller gearing (from a larger diameter tire) will screw up the truck designer's carefully calibrated computer settings. Sometimes at least. In the old days taller gearing would usually improve mpgs, but that isn't the case anymore.

Mostly we just pick what we like/want/need and live with the resulting mpgs. I do wish more of these tires had rolling resistance info though, so we'd at least know that value.

 

[billiebob]

Mostly we just pick what we like/want/need and live with the resulting mpgs.

yes, that was me until last year
I was not expecting such a dramatic result.

Also incredible is how much farther these tires will coast than the 33s I was running.

 

[rruff]

What's the brand/model?

 

[billiebob]

What's the brand/model?

?????

 

[rruff]

?????

Of the tires you bought that improved MPGs.

 

[billiebob]

Yokohama 742S 7.50R16s

See post #49