Tire weight - how much does it matter?

[Champ]

I thought the only important issue, was how good they look? I tried some sweet 15" very light wheels on one of my rides, but they just wouldn't fit over the calipers!

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[fbov]

Actually - I've been really curious for the Hybrid. Steelies aren't....light. ...

I had snows on steelies on my C-Max, replacing alloys. No difference in mileage, beyond the temperature effect.

So physics question... So for someone who does lots of stop and go driving would they see worse MPG with a heavier tire than someone who does freeway?

Not if they're driving a hybrid, which can recapture up to ~90% of the energy through regenerative braking. Stop and go (slow) can give much higher mileage than freeway (fast) driving with a hybrid.

 

[es7129]

If concerned about weight and efficiency, biggest decision IMO will be to decide if you want the compromises of all terrain oriented tires.

When people rate the performance of these, its usually relative to other all terrain tires, and not road focused ones.

I mean, if you really want a cost savings tire you'd want to look at eco tires that are specifically made to reduce rolling resistance and stick to the 225 factory width and have a decent tread life since replacing tires often can be as expensive as buying a lot of fuel.

I have these Michelin Defender LTX for that reason on my Ram 1500 and have been very happy with them, especially in the rain: https://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Defender+LTX+M/S

In 225/65/17 they are 29lbs and 720 wear rated in spite of having pretty darn good dry traction and are $70 off right now.

I'm fairly confident these would be objectively better in most measurable ways on the street thanks to the street oriented tread pattern design, but they aren't going to have that rugged offroad look to them or of course be offroad capable tires, but for the type of dirt roads I've taken my RWD Ram down they'd had no problems.

Fwiw Nokian WRG4 and Rotiiva AT Plus are LRR rated tires.

 

[JASmith]

Doesn't help you, but found it interesting that on a large F150 forum, for 20215-2020 generation F150, when you search tires, unsprung, weight you get multiple pages of threads. Nothing definitive on ride quality, lots of opinions (but not so much hard data) on mpg loss. For the Maverick time will tell as experimenters list their wheel/tire swaps and discuss ride quality and mpg's.

The definitive rule of thumb that has been tested on dynos is that every 3lbs of wheel/tire weight is about 1hp loss at the wheel.

So lets compare BFG KO2: 45lbs x4 = 180lbs , Michelin Defender LTX 29lbs x 4 = 116lbs

64lbs difference / 3 = 21whp lost. The less powerful the engine, the more obvious such a difference, so a Hybrid Maverick likely makes 168hp at the wheel - 21whp = 147whp or about a 12% loss of power. With a Ecoboost the power loss would be only 9% difference, and on something like a 6.4 liter Charger Scat Pack would only be 5% so you start noticing less and less.

Fuel economy should be minimally impacted by weight IMO, as most of the time you're not accelerating. The rolling resistance and perhaps wind resistance of the tire would be the biggest factor.

 

[Big Kahuna]

Nokians have taken a big turn downward in the last couple of years in my opinion. I was their biggest fan previously. Had them on all my vehicles. Amazing in the snow and rain, only issues were wear and road noise. Fast forward and their latest designs seem like much more of a compromise, we had multiple issues with flats/sidewalls and their wear somehow got worse.

As far as size I'm not going bigger than 245's on the truck, it's just not built for it.

 

[JASmith]

I thought the only important issue, was how good they look?

Cool factor definitely matters, but IMO you don't have to go with true all-terrain tires to look like they belong on a truck, and you can still do light off-roading without the sacrifice in highway drone and reduced street traction of an all terrain pattern.

 

[MakinDoForNow]

So physics question - a object in motion tends to want to stay in motion. So it takes more power to get it rolling but once it's rolling it will have more momentum than a lighter tire.

So for someone who does lots of stop and go driving would they see worse MPG with a heavier tire than someone who does freeway?

I would see a little less mpg primarily that due to increased brake pressure required to slow the momentum the hydraulic brakes would be called on more frequently. May not be enough to matter at all. I am hoping to see something on dash green= Regen brake only, yellow=Regen & hydraulic, red=hydraulic only. But none of the designer dudes ever called me.

Also check out the Nokian Rotiiva AT. In 245/65R17 they're only 31.2lbs.

245/65 R 17 111 T XL T428192 31.2 7-8.5 7.0 29.5 9.8 13 705 438. From spec chart shows 31.2 lbs approved fit 7-8.5 rim with range - next is 7.0 measured rim - then next is diameter 29.5" so 1" over. I do like this tire very much due to fibre reinforcing sidewall and the extra load rating. I am going to look into their low rolling resistance tires also. Thanks

 

[PortlandME]

Does wheel weight matter too? Does anyone have the stock wheel weights? I assume the steelies on the XL are heavier than the aluminum wheels on the other trims. Seems like if a few pounds was enough to effect mpg then the EPA numbers would be different on the different trims? (Of course, that assuming that the steelies are in fact a few pounds heavier per corner).

 

[vabchusa]

I use Michelin Energy Saver A/S tires on my C max inflated to max pressure. Excellent tread life and great mileage ( 41.7 over 6 yrs and 166000 miles) A Goodyear rep (personal friend) once told me that the most efficient tire pressure is 5 lbs OVER the max

 

[JASmith]

I use Michelin Energy Saver A/S tires on my C max inflated to max pressure. Excellent tread life and great mileage ( 41.7 over 6 yrs and 166000 miles) A Goodyear rep (personal friend) once told me that the most efficient tire pressure is 5 lbs OVER the max

Yeah, it reduces the contact patch to run over pressure. Also get bad ride quality, less traction, and uneven wear on the middle of the tread though.

 

[Darnon]

Fwiw Nokian WRG4 and Rotiiva AT Plus are LRR rated tires.

The AT Plus are only LT sizes and heavy. The regular Rotiiva AT are LRR as well, though.

 

[TSAINTS1115]

Fuel economy should be minimally impacted by weight IMO, as most of the time you're not accelerating. The rolling resistance and perhaps wind resistance of the tire would be the biggest factor.

I think it would depend on where the majority of driving occurs. All highway would follow your theory of the two resistances being greater than rotational weight. In a majority city stop and go scenario I feel the acceleration/deceleration of the mass repeatedly would factor in the mpg more.

 

[TSAINTS1115]

Does wheel weight matter too? Does anyone have the stock wheel weights? I assume the steelies on the XL are heavier than the aluminum wheels on the other trims. Seems like if a few pounds was enough to effect mpg then the EPA numbers would be different on the different trims? (Of course, that assuming that the steelies are in fact a few pounds heavier per corner).

Weight is weight. Physics doesn't care what the material makeup is. 25lb steel wheel vs 25lb aluminum.
What WOULD make some difference is where the weight is in the wheel. The greater percentage of weight at the hub would be easier to get rotating that the greater amount of weight out at the barrel.

 

[PortlandME]

Weight is weight. Physics doesn't care what the material makeup is. 25lb steel wheel vs 25lb aluminum.
What WOULD make some difference is where the weight is in the wheel. The greater percentage of weight at the hub would be easier to get rotating that the greater amount of weight out at the barrel.

Right, my point was it may be a 30lb steel wheel vs a 25lb aluminum wheel (purely hypothetical #’s).

 

[TSAINTS1115]

Right, my point was it may be a 30lb steel wheel vs a 25lb aluminum wheel (purely hypothetical #’s).

But it would also factor as to where the weight was distributed. 30lb S with mass at the hub vs 25lb A with mass in the spokes out at the barrel.

Take a 10lb barbel in your hand with arm straight out. You can twist your wrist back and forth for some time without feeling it. Take the same barbel and windmill that puppy and see how it changes everything.

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