Narrower Wheels or Lighter Wheels???

[GasSavers_BMac]

Ok, I have a set of aluminum Dakota wheels that are 8" wide. I swapped them out for a set of steel 7" wide wheels.
Which is going to help in mpg gains if the aluminum ones are lighter?

[lca13]

I vote the lighter wheels as there is less energy expended every acceleration (the angular momemtum increase and decrease will be less).

[brucepick]

I'm sure you'd need a wind tunnel to really nail it down however...

The aero profile of the wheel + tire is going to be determined by the tire's section dimension - the first # in the tire size. Both your wheel sets are going to be narrower than the tire's section dimension since the sidewall bulges out from the rim.

Based on that on piece of information only, I'd say the lighter wheel would win. However if it's aerodynamically very busy, and the wheel covers on the steelies are basically flat and smooth, then the steelies might be a better choice.

Of course steelies have virtually no bling appeal. Paint wobbly concentric rings on them to confound your observers.

[VetteOwner]

well i went from like 6" stock steel wheels to 8" aftermarket steel chrome wheels and didnt notice any difference in MPG. well nothign that couldnt be accountable from driving differently.

[GasSavers_Graeme]

When I bought my xB I went from steel to Enkei aluminum wheels. Saved right on 8 pounds per wheel. Kept the original 15" diameter. So my xB went from 2415# to 2383# and I reduced the rotating mass and the unsprung weight. All winning moves. The only think I wish is that the wheels were a bit more aerodynamic. I'm thinking of Moon discs, but that blasphemes the Enkeis.

I'd vote for aluminum wheels--if indeed they're lighter. Use a scale. Larger diameters may weigh more than steel.

[lca13]

Consider that Honda put aluminum wheels on the VX, unlike most of the other models.

Any mass reduction in the drive train is a win. The performance guys even replace the flywheel for a few extra HP.

[GasSavers_BMac]

Ok, then I guess I'll go back to the original meaty wheels. I felt more secure in the turns with them anyway.

Thanks

B~

[psyshack]

You need to weight the wheel and tire combos.

A narrow plus light wheel tire combo will always be better mpg wise.