largest tire without gas milage loss

I’m not skeptical nor said that tire/wheel weight doesn’t decrease efficiency. What I am skeptical about is if weight is a significant factor compared to rolling and air resistance.

Speaking of bicycle tires, it is much more common in the bicycle community to talk about the rolling resistance of a tire. Possibly because it is much more intuitive because you can literally feel the effect of a low rolling resistance bicycle tire.

 

That would depend on how the truck is driven. If it was driven out the driveway and kept at 80mph for a few hours, I would think heavier tires with the same tread and size as a lighter tire would have little difference in this case. If one drives in the city, and never gets past 30 mp/h, heavy tires would make a huge difference.
The bicycle experiment would solve the rolling resistance question as well.
In the road cycling community, yes, rolling resistance at different pressures is as important as weight. When it comes to mountain biking, weight is far more referenced than RR.

 

Understood. Wind is number 1.
Vehicle weight is number 2.
Rolling resistance in number 3.
Unsprung mass, which includes your tires, is number 4.

But by far and away most important is your driving habits.

 

There's the limit right there: Exceed it and the gas mileage WILL tank. Someone had to step up and say it: Thank you.

 

Tank tread > All.

 

Listen to this man, he's right: He'll never admit it, but obviously he went to CalTech Poly and now works for the JPL... WFH in Europe or something in a group that will never tolerate him ever speaking to me. or maybe went to state college like me: he's smart and he's right.

 

215/85 r16s FTW.



Seriously.

 

I don’t disagree with this for the most part. I think you might still be over estimating the effect of rotation inertia on fuel economy though. There are some calculators on the net with all the math and physics explained. Here’s one:

http://hpwizard.com/rotational-inertia.html

By the author’s approximation, each pound of tire is equivalent to 2 pounds of payload. So, for example, a tire that is 10 pounds heavier is equivalent to putting 10*4*2=80 pounds in your bed. Do you think a 80lb dog affects the gas mileage of 4600lb truck significantly? I’m skeptical. Could it be some other aspect of the tire making the truck slow and inefficient? Rolling resistance? Air resistance?


I do not doubt that there is a significant correlation between tire weight and fuel economy, but doubt there is a significant cause and effect relationship. I could be convinced otherwise if someone put forth a convincing argument.

 

I had 245/75/R16 E rated BFG KO's on stock steel wheels that came with the truck. I bought a second set of alloy SR5 rims with Firestone Destination LE2's the same size. My mileage immediately increased 10+% on the LE2's, similar weather, similar driving cycle. Acceleration was notably improved. 18 lbs difference per rim/tire combination lighter.
I have since purchased new E rated Firestone Destination XT's in LT215 85/r16 that are 1.5 lb per tire heavier than the LE2's. They too are mounted on alloy Tacoma rims. My mileage is similar to the LE2's. Fuel economy is about 2% worse over 5000km's/10months of driving
I don't know why I am trying to convince someone that lighter wheels and tires are far more efficient and the best place to save weight on a vehicle.
It should be the other way around. Convince me otherwise.
And there is no actual proven formula as to the effects of unsprung weight that I know of. I've heard number thrown around that the difference can be between 2-6 lbs payload equals 1 lb unsprung weight.
So, in my documented experience, given that the LE2's rim and tire weight was 58.4lbs, and the KO's of the same size were 76lbs, it would appear that each 10lbs of rotational unsprung mass increases fuel consumption app. 6% with the same control vehicle in similar conditions. These numbers would probably be different with a 6 cyl. Tacoma.

 

I agree. I even think the 6 cylinder wouldn't be a whole lot of difference. Every time you increase the rotating mass its takes more hp to get the same results resulting in a less efficient vehicle. You can't argue with physics.

 

at least not in this astral plane…

 

I have 3 complete sets of tires for my taco and here is my results. The factory black rims and tires are 245/75r16. 19 to 21 5 miles to and fro to work. Bought a set up 265/70 r16 with aluminum forerunner rims and mpg is pretty much the same. Bought ironman at's 245/75r16 with slightly heavier 2007 forerunner rims and the same treck to and fro work i lost about 1 to 2 mpgs. Same gas station always, airdam still there, and ARE huge camper shell. Acceleration and braking feel the same, but i baby my truck 98% of the time. Pics below

 

Sorry about multiple pics, still learning

 

Next time i change tires i will weigh all 3 and give results

 

Largest tire is 255/80/17 without too much mileage loss

 

/Closethread

 

And with the right offset wheel, no trimming of anything required.

 

What offset is best Serge?

 

Depends on the tire. I've seen some tires weigh 40% more than the same sized P rated tires. And then there are rims...

 

Sema rims with a 4mm offset seem to be the sweet spot.

I cycled my suspension off-road and no rubbing anywhere.