smooth wheels/hub caps = MPG increase?
 

I'm looking to hear from anyone who has kept THE SAME tire size, but either added smooth (plate/dish-like) hub caps to the wheels OR found the same smooth type of wheel to replace their pre-existing ones. I would like to know if this change resulted in increased MPGs.

I swapped my stock CRX HF (steelies) rims for a set of those superlight Mazda Miata BBS (mesh-style) rims. The BBS are in NO way a smooth pattern; they probably stir up all kinds of turbulence. Although I love the look of the rims, they (along with their somewhat LRR & lighweight tires) didn't boost my fuel economy. Now, I don't know if there's a chance that any gain may have been offset by the fact that the wheels are not as smoothly patterned as the stock steel HF rims. I do know that I'd just like to hear from anyone who HAS deliberately swapped to a smoother wheel pattern...and whether or not they experienced a gain/loss in FE. Thanks a bunch for any/all info.

Try googling "Baby Moon" hubcaps. They are aerodynamic, originally deigned for racing.

Take a look at this post...
https://www.gassavers.org/showpost.ph...99&postcount=2
in the image you can read...
"We also tested the moon discs which reduced drag by two to four counts. The farther the wheels are from the outer edge of the fender, the less the discs matter."

this is what i've put on since a couple of days they came from my dad's old ascona that's due for the scrapheap.

https://www.fuelly.com/attachments/fo...125ac5fd1f.jpg

don't know if they're helping... the car feels a little different but that might just be from the extra weight or because i know they're on.

they don't inhibit cooling if that should be an issue but they're pretty clean otherwise... they also make car car look more modern than it is :)

Any chance to put those stock HF steel wheels on a scale and compare them to the alloy wheels you have?

Sure...
 

I actually did put them on a scale. The stock HF wheels are 13" X (4.5?)"...anyway, they weight in at just a hair over 13LBS., if memory serves. (I will weigh them again both with and without the little "H" caps).

As for the Miata BBS rims, they're definitely lighter, by 3LBS or so...and larger too. The Miata rims are 14" X 6"...and the tires I got for them were Nokian's that came off of a Prius :thumbup: The tires are 175/65/14's that are even lighter than the tires that were on the HF steel wheels. I did my homework on this swap! The Nokians can also handle 50psi, no problem -(not that I wasn't already doing that with the Aquatred-3's that were on the HF wheels...I was!).

Road Warrior, thanks for that link/article. I sure hate it when good looks pose a threat to FE. Well, I suppose in order to find out whether or not my new, lighter wheel/tire combination had a net ZERO effect on gas mileage (i.e., lighter overall combination with possible aerodynamic drag = no FE change?), I'd have to find a different wheel/tire combination of equal weight, but WITH a smooth flowing pattern (and keep certain that they remain an equal distance from the wheelwell when mounted on the car). That should tell the tale. **OF course, there's always the chance that dropping a few LBS from the (front/ FWD) rotating masses just HAS NO change with this car...as the OEM wheel/tire combination was not a tremendous amount heavier.

Sludgy -

I used to google that, but "racing disk" is probably better. This ain't cheap, but these are the real deal :

Moon Discs
https://www.mooneyesusa.com/Store/in...2de15d5fb11671

CarloSW2

Since you have lighter wheels/tires, have you tried shifting gears at lower rpms? The ligher wheel/tires should let the car accellerate easier.
I've noticed a slight difference when I installed a lighter flywheel on my car.

prolly lost a bit of torque in swaping flys tho...
should rev faster and slow down faster but torque is lost

oh my chevette i have almost baby moon hubcaps and then i have the stock windmills. it doesnt make a difference either way. of course the cars high up and lot of frontal tire space, but also very skinny frontal tire space...