Tires/fuel mileage?

[Gstick]

Serious question.

Will I notice a fuel savings going from a 46lb tire (LT265/70/17) to a 39lb tire (P265/70/17) on stock OEM 17"x 7.5" wheels?

In my mind, if I can gain 1.5-2 MPG in gas, it will be worth it for me to go to a 7lb per tire weight savings.

Just not sure if it will be noticeable?

 

[gordonp]

I have both

(both a new set of OEM Bridgestone Dueler, and a set of BFG KO2's).

I just changed back to the Bridgestone OEM tires (which happen to be brand-new take-offs from another guy, who sold them on Craigslist). I spent the 3 years before this change-over using the Load E BFG KO2's. Both sets are stock-size.

I have measured about 0.1mpg improvement with the OEM Bridgestones.

But, the Bridgestones are more-enjoyable on the highway (quieter).

And, the Bridgestones heat up such that the TPMS shows my tire-pressures increase about 1-pound after 1hr highway driving (confirmed just an hour ago, today). The BFT KO2's will increase by about 3psi in the same conditions. From this, I infer that the Bridgestones are running cooler, and/or the lighter sidewalls can shed heat more-easily.

I run the Bridgestones at 34psi front / 33psi rear.
I run the BFG KO's at 51psi front, 48psi rear.
(the difference is roughly meant to equalize the rolling-radius front to rear, accounting for the greater (engine + stuff) weight up-front. Thus, in 4WD, both front and rear are more-likely to pull an equal share of the traction, rather than one slacking and doing nothing until the other slips a bit)

I enjoy both,when I look for what they're each good at. Quiet and smooth, versus stiffer (trailer-towing), tougher, and better in snow + offroad.
But I don't think there is any way on earth you'll see 1.5 - 2mpg improvement.

HTH!

 

[Gstick]

Thanks for the input.

Probably wishful thinking on my part about the fuel savings, but it doesn't hurt to ask.

Thanks again!

 

[6439Flouride]

Interesting question. Obviously the energy required to spin up a heavier tire is greater than what a lighter tire requires. The type of driving you do would also be a factor (stop-and-go vs. open road). Rolling resistance could be a factor as well, do the tires differ significantly (I'm thinking knobbies vs. slicks, on a mountain bike vs. a road bike)? What about the cost of the tires?

Mine came from the factory with P265/70R17, right now $285 each at Costco. Not all, but most of the LT265/70R17 are more, some as much as $400 each.

If you're going after fuel efficiency, is the tire cost insignificant? What about the expected lifespan of the tire? Seems like the P265 tires tend to have a mileage warranty which exceeds the LT265 tires, at least from what I see.

 

[Gstick]

I am currently running BFG KO2's in LT 265/70/17 Load Range C which weight 46 lbs each. I don't go off-road enough anymore to justify the ruggedness and weight of these tires so I'm pretty sure that I'll go with the Yokohama Geolander AT/4 in P265/70/17 which weigh 39 lbs. I was just curious if the losing of 6-7 lbs per corner would be a noticeable fuel savings. I have had Yoko's A/T's years ago on GM 1/2 ton 4x4's and really liked the traction and ride both in the snow and on-road. I tend to be a brand loyalist when it comes to tires which really isn't a good thing considering today's advanced technologies.

 

[02SE]

It's not just tire weight that matters. Tread pattern, tread depth, tire compound, casing construction, and inflation all play a part in MPG.

All else being equal, a lighter tire would get better MPG. But we don't know how the variables add up when comparing the BFG, and the proposed Yokohamas.

P-rated tires typically have shallower tread depth than LT tires, so that would help when only considering MPG.

 

[CutthroatSlam]

Can’t speak for BFG, but the durability difference between C-rated Cooper AT3 and LT or E-rated Cooper AT3 is 60K miles for the C-rated vs 90K for the E-rated. This is based on actual experience.

 

[6439Flouride]

Anecdote ≠ data, but in the past we drove a first generation Sequoia. Tires were purchased at Costco.

Over a twenty-year span, we pretty much followed the warranty rotation schedule as required. Every 5K miles, documented rotation, pretty much.

The tires for that Sequoia were never cheap, but we never off-roaded with it. Urban and suburban driving, proper inflation.

Yet I can't recall a single time we ever achieved the warranty mileage. In other words, if we spent $1,000 for a set of Michelin tires warrantied for 70K miles or whatever, they would typically be worn out by 30K-40K miles. Worn out to the point that Costco would refuse to rotate them. So we would replace them.

Because of our documented tire rotation, we would claim warranty relief with proration, meaning if our tires had lasted for 60% of the warrantied mileage, for example, we would get 40%, give or take, off the next set.

What I am saying is, well and good to consider tire weight, cost, rolling resistance, gas price, driving style, etc., but even if you get a set of wonderful LT265 tires for $1600 or whatever, that is a good purchase only so long as your cost per mile justifies it.

For us, I want to say that we got new tires for that Sequoia every 30K miles or so, prorated 80% of the time. Five or six sets of tires while we owned it.

Even our seasoned trusted mechanic said that Costco Michelin Tires, they never get to the warrantied mileage, but lots of people miss out on the warranty relief because they just don't follow the required schedule. Gotta keep first things first...

 

[Yamahamer]

It's not just tire weight that matters. Tread pattern, tread depth, tire compound, casing construction, and inflation all play a part in MPG.

All else being equal, a lighter tire would get better MPG. But we don't know how the variables add up when comparing the BFG, and the proposed Yokohamas.

P-rated tires typically have shallower tread depth than LT tires, so that would help when only considering MPG.

^This!

Check out Consumer Reports tire reviews and they will show you ratings for "rolling resistance". One of the reasons I chose Michelin Defender LTX tires for my 4R was the low rolling resistance (consequently better fuel mileage).
My overall fuel mileage over the past 28000 miles is 22.8 mpg.

 

[Mrvmax]

I wondered that myself, my wife’s 2019 has stock Dunlop’s and mine are larger Bridgestone that the dealer added when new. Hers gets 1-2 mpg better than nine consistently and both need new tires this year.

 

[curmudge1]

I recently drove my 2012 TE from NJ to Fla to give it to my brother... 203K miles when I transferred the title. Before I left, I had the transmission, differentials, and transfer case fluids changed, and the spark plugs changed.; I changed the air filters; last summer the EFI cleaning (basically throttle body), and coolant changed. Everything you could do to get better mpg for a trip.
1,200 miles or so, and I got about 22mpg or better consistently for the trip. Sometimes the dash showed higher mpg for awhile, like 24 mpg. I wasn't poking along, not too many traffic slowdowns. Tires at 35 psi. No lift, Bilstein 4600s. I'm used to seeing 18 to 20 mpg mixed driving. YMMV. FWIW.

I'll be switching to the Defenders on my newly acquired 2019 TRD OR this fall, kind of waiting to see if there's a rebate. The AT tires it came with ride pretty firm, and noisier than the Defenders.

^This!

Check out Consumer Reports tire reviews and they will show you ratings for "rolling resistance". One of the reasons I chose Michelin Defender LTX tires for my 4R was the low rolling resistance (consequently better fuel mileage).
My overall fuel mileage over the past 28000 miles is 22.8 mpg.

 

[henley]

I’d be curious about this too. Seven pounds per tire seems significant, but I wonder how much of a real-world MPG difference it actually makes.

 

[DAW89446]

'18 SR5, stock. I run stock size BFG KO2s, load range E. I live on a dirt road, lots of dirt roads in the rural area I live. I live with sharp gravel, dust, mud, snow, ice. And I don't like flat tires. I also have plenty of Class IV trails nearby that I travel during upland game season.

A fraction of a mile per gallon savings is worth nothing if I don't have a reliable tire. I've run BFGs on three rigs over the past three decades without a true failure.

If I want real MPG savings, well, I have a '12 Subaru Outback for that. It's been a darned good car.