MetroMPG.com mailbag: what about lightweight rims?

[MetroMPG]

Your point about it being a fractional gain is valid.

But I'm in it for fractional gains too. At some point, the low hanging fruit has been picked. And unfortunately, not every pulse ends in a glide.

So, if I can save 30 lbs by removing the passenger seat, vs. 30 lbs by swapping wheels (I think that's what Ben saved going to VX rims from his stock steelies), I'd still do it. (Actually, I'd probably do both.)

[roflwaffle]

But at what cost would you still do both?

[MetroMPG]

That's easy: at an affordable cost!

[roflwaffle]

I knew you would say something like that...

[DifferentPointofView]

uh... this really doesn't have to do with lightweight rims, but it does have to do with rims. Would packing the rims with snow so they resemble pizza cutters improve mileage or diminish it? My rims if you look at them are pretty smooth, but if I packed them to be solid white circles would that help? it's nice and snowy here and using the weather to my advantage instead of my enemy is my favorite thing.

[Beaver]

Recently I read an article in Hot VW's in which a fuel mileage oriented air-cooled VW engine was being built. They intentionally used heavy rotating and reciprocating internal parts in the engine, including a heavy flywheel. I think their point was that the engine would store and hold on longer to the energy invested in it to get it up to speed. It seems like this idea plays into your "pulse and glide" tactic. Heavy wheels and tires should also act as flywheels, causing you to be able to glide further, shouldn't it? While it may take more energy to get up to speed, it will keep that speed longer(?) If this is so, maybe it would be better to save weight elsewhere on the car, and go heavier on wheels/tires.
As a weekend autocrosser (G-Stock Neon ACR) I am very aware that lighter wheels/tires are much better for performance and handling, just as a light flywheel and light pistons/rods etc. makes for a more responsive and quicker revving engine. But are they best for fuel economy for those using techniques such as those hypermilers use? I don't know, but I just bought a '96 Geo Metro 3 cyl 5-speed for my daily driver and want to try my hand at this fuel mileage game. I'd like to know what you think.

I know, I know; autocross seems like such a waste of gas! But my Neon probably gets better mileage on the course than most of the other cars out there; it's only about 45 seconds per run; it makes you a better driver, and it's FUN!!!

[Frederick]

I wouldn't pack any wheels with snow. Density of your pack picking pursuit is bound to be different at certain places. Bounce and erratic wheel behavior will ensue. Perhaps life stopping death. Now, we don't want that happening to you.

[trebuchet03]

While it may take more energy to get up to speed, it will keep that speed longer(?)

Likely ranging from a wash to negative... Energy in - losses = Energy out. You'll be able to glide longer (just like adding any weight to your car), but you'll have to put more energy in :/

[Coyote X]

I think it would be a reasonably easy thing to test if you have access to the stuff needed.

Find a tire shop that they know you at and borrow all their wheel weights and stick the entire lot on your car's rims

Then you can test and see how much that changes things. It should be easy to add a few pounds to each wheel so on a small car with small tires it should be measurable if it actually does anything. You could also measure the changes in how it does pulse and glide, if it glides farther for just a tiny bit longer pulse or if the longer pulse is equal to the longer glide.

Just keep track of where the old wheel weights go so when you take them off you don't take the originals off.

[Kevinr]

These 13 inch rims are just 11 pounds and should work for your metro! geometroforum.com/topic/4271097/1/