How much does tire and wheel weight effect MPG?

[gumby79]

Most "H" or fasters speed rated tires eather have no load capacity or are 28" or smaller or10-30"wide drag rears.

To day I've found some options

32.18"D 235/55r22 (104w) 1984lbs 168mph $154 usd


31.41"D 275/25r26 (98w) 1653lbs 168mph $215 sud


30.04"D 255/50R20 (109Y) 2271lbs 186mp
From #14
http://ecomodder.com/forum/showthrea...0-a-35805.html

There is also a 32.68"D 315/35R24 w
Stock 31.7"D 235/85R16 LT S speed rating. Yielded 87.14mph 1:03279 standing mile.
What kind of impact should I expect ?
Going to a smaller speed rated tire requires installing a Bonneville specific quick change rearend for gear, just to get to 130mph @2500 RPM.

[freebeard]

Originally Posted by Effic1ent1

The real question is should I cover the nice new wheels with coroplast?

Needs pictures. These ones?


http://i.ebayimg.com/00/s/MTA2NlgxNj..._id=8800005007

No.

Coroplast is cheap and impermanent. If you want cheap get Moon disks and zip-tie them on. To do justice to what you have, there is a particular JDM wheel that was a spoke wheels with a dished cap that fit into between the spokes as an aerodynamic upgrade. If I remember what it's called I'll come back and edit this. You could make something similar by indexing a cap and cutting 15 notches in the rim.

Else, a center cap with left/right handed knock-offs that just hold the disk.

[mpg_numbers_guy]

Originally Posted by Effic1ent1

The real question is should I cover the nice new wheels with coroplast?

The real question is, why not? How important are aesthetics to you?

[Effic1ent1]

Originally Posted by freebeard

Needs pictures. These ones?


http://i.ebayimg.com/00/s/MTA2NlgxNj..._id=8800005007

Those look like the backs.

Originally Posted by mpg_numbers_guy

The real question is, why not? How important are aesthetics to you?

I was just kidding really. Only on ecomodder's do you take a nice new set of alloy wheels and cover them with cheap black plastic, even if they did cost next to nothing. That being said, no I don't really care about aesthetics and I might still cover them up.

[California98Civic]

Originally Posted by Effic1ent1

... I was just kidding really. Only on ecomodder's do you take a nice new set of alloy wheels and cover them with cheap black plastic, even if they did cost next to nothing. That being said, no I don't really care about aesthetics and I might still cover them up.

Hahaha! FWIW, I would not cover such rims with cheap plastic. I would sell them and buy crappy rims & good LRR tires!

[Vekke]

https://www.linkedin.com/pulse/impac...28gr75qA%3D%3D

Here some pondering. very little impact. I have calculated 0,2% savings in Tesla Model Y with 24kg less rotational mass.

Here they calculated 0,4% in the example

[catmwarrior]

Tire weight is very important. The less weight, the quicker you vehicle can be, and the less energy or fuel will be use to get up to and maintain speed. You can search this on the web. Every seven pounds you take off your rotational mass (alloy rims, light tires, alloy axles and driveshafts) is like taking 100lbs of weight out of the car.
Imagine riding your bicycle, well then take seven pounds or more of fishing weights, and add them to your spokes. It will take a lot more effort to pedal that bike. You may not notice with your vehicle because it has so much more horse power than you, but your fuel mileage will notice it.
Tire width also is important, but you can look into that on your own. Every seven pounds you take off of your rotational mass, you will gain 1/8 of a mile per gallon. My jeep, factory rims and tires I averaged 28MPG. After I swapped out; Allow driveshafts, ultra light rims with low rolling resistant tires, I averaged 33MPG at 55MPH.

[Piotrsko]

One would also need to account for flywheel rim effect accellerating and deceleration which effects energy in and out of the system along with steady state operations

[aerohead]

Originally Posted by catmwarrior

Tire weight is very important. The less weight, the quicker you vehicle can be, and the less energy or fuel will be use to get up to and maintain speed. You can search this on the web. Every seven pounds you take off your rotational mass (alloy rims, light tires, alloy axles and driveshafts) is like taking 100lbs of weight out of the car.
Imagine riding your bicycle, well then take seven pounds or more of fishing weights, and add them to your spokes. It will take a lot more effort to pedal that bike. You may not notice with your vehicle because it has so much more horse power than you, but your fuel mileage will notice it.
Tire width also is important, but you can look into that on your own. Every seven pounds you take off of your rotational mass, you will gain 1/8 of a mile per gallon. My jeep, factory rims and tires I averaged 28MPG. After I swapped out; Allow driveshafts, ultra light rims with low rolling resistant tires, I averaged 33MPG at 55MPH.

* With ecomodding, what's important to us is, what's the difference at an identical rate of acceleration.
* Once up to cruise velocity, energy losses during braking can actually be 'harmed' with a mass reduction, considering hybrids, plug-in hybrids, and full BEVs.
* A rather remarkable difference in all-up weight will be necessary, in order to experience ANY change to rolling resistance-related power absorption and mpg, even if BSFC is known to be constant.

[steve05ram360]

Throttle response changes with heavier tires, the same for lighter wheels. If you drive 400 miles (example) non stop on the hiway then there may not be an impact but over a mixed tank where your starting/stopping it does impact mpg's.

one lb off an engine pulley was enough to see the throttle response change and enough for me to go after the remaining pulleys and driveshaft.










when I did the driveshaft I lost boost rpms, meaning it was starting to come off ambient pressure at approx 1400 rpms. After the DS install it was up to 1600+ rpms. Found out the areas in the tune where timing is key for boost (diesel) were no longer being hit. Changed the slope of the timing curve and got those 200 rpms back and once seeing the cause & effect, went after more boost down low. Ended up getting boost coming off ambient pressure all the way down to 800~900 rpms. Engine is always under boost now.

With all that and then some, got my truck up into the 22+ mpg's range with a peak at 25.0x & a couple of 24's. Had that for 2~3 years then needed new tires. Unfortunately they are stickier & heavier which impacted mpg's (now in the mid 20's :-( )

Weight matters...