Hubcaps?

[DracoFelis]

Do smooth hubcaps (for example, a "Baby Moon") help with FE? Has anyone tried it? If so, how much did it help?

This seems to me like it might be one of the easiest aerodynamic mods to make (since you just buy the hubcaps, and put them on). And it is pretty cheap to buy a set of hubcaps. But does this help? My thinking says it could go either way:

1) It might hurt FE, because the wheel covers will weigh something, and this will (slightly) raise the weight the wheel has to turn. OTOH this added weight isn't that high (especially compared to the weight of the tire and wheel itself).

2) OTOH it might help FE, because smooth hubcaps should make the wheels more aerodynamic, by covering over the places the air can get trapped in.

Either way, this mod should be reasonably cheap and easy to do (just buy a set of hubcaps, and put them on). And unlike some aerodynamic mods, this one isn't likely to draw a lot of attention to itself (as many people snap hubcaps on their wheels). And it should even cover up the rust on the wheels themselves. ;)

But has anyone tried this (and if so, how well did it work)?

[ketel0ne]

See this thread.

http://www.gassavers.org/showthread.php?t=1449

On a side note I am kicking around putting them on my Yaris.

[ZugyNA]

Somebody just did full moons...even had pics.

http://www.jcwhitney.com/autoparts/Product/Pr-p_Product.CATENTRY_ID:2003995/c-10101/Nty-1/p-2003995/Ntx-mode+matchallpartial/N-10101/tf-Browse/s-10101/Ntk-AllTextSearchGroup?Ntt=hub+caps

http://www.jcwhitney.com/autoparts/Product/Pr-p_Product.CATENTRY_ID:2003985/c-10101/Nty-1/p-2003985/Ntx-mode+matchallpartial/N-10101/tf-Browse/s-10101/Ntk-AllTextSearchGroup?Ntt=hub+caps

[SVOboy]

As a general rule of thumb, I think aerodynamics > weight for FE.

One of the newer members just did this actually, but I haven't seen any results yet: http://www.gassavers.org/showthread.php?t=1449

I say go for it. Basjoos has done it as well. Other people I'm forgetting at the moment, sorry guys/gals!

Edit: Damn, I got pwned.

[MetroMPG]

My wheel covers are also smooth, but they don't necessarily look it in the photos due to my awesome fabricating skills. :rolleyes:

Some actual figures to chew on:

Indeed by completely sealing all four rims, Cd can be reduced by 0.08 to 0.012 (ref. 6). The maximum drag difference between a good and a poor set of rims is probably even larger.
Source: Contribution of different devices to the total drag
http://www.tfd.chalmers.se/~lelo/rvad/reports/rva2002_gr11_contribution-to-drag.pdf (http://www.tfd.chalmers.se/%7Elelo/rvad/reports/rva2002_gr11_contribution-to-drag.pdf)

There's a section in that report devoted specifically to wheels, rims and wheel housings.

Edit: my wheel covers were pretty well designed to begin with, so my gain is likely on the small end of the scale (and further reduced by the rear wheel skirts). Small enough that I haven't tested it, and probably won't bother.

http://images6.theimagehosting.com/wheel-covers-aero-1.th.jpg (http://server6.theimagehosting.com/image.php?img=wheel-covers-aero-1.jpg)

[Matt Timion]

Once I get my 14 inch tires (Ahem Bunger) and LRR Insight tires, I'll get some smooth hubcaps too... why not?

[lindermant]

I'm working on my first full tank with the moon caps installed... I'm only about 200 miles into the tank, and I'll be out of town for the next two weeks after I get off work Friday morning so I won't have data to share for awhile (unless I decide to fillup on my way home - but I hate short-tanking).

No promises, but my SG tank MPG reading is showing a tad higher than my last tank of 50.16MPG, which was a personal best.

No issues with brake temps, but the darned things are noisy at slow speeds!

[Ryland]

I rather question my vx rims at times because of my expearince with bicycle wheel airodinamics, the spokes of a bicycle wheel work alot like an egg beater, each spoke stiring up the air, thus the justifide demand for blade like bicycle spokes for racing, and me left wondering how good the 8 spoke vx rims really are, so it makes sence that the hybrid civic has wide flat spokes, and the insight has near disk rims with smal vents around the outer edges, so the worst rims you can get, airodinamic wise would be the ever so popular thin spoke large diamiter alloy rims (the spokes look thin, but are really wide flat blades, like a whole bunch of little fan blades...
We just got some of the spun alluminum Moon hub caps for the metro, but we haven't owned it long enough to have a solid feel of the mileage, nor do we have a scangauge yet and I haven't taken the time to find out what they weigh, but I'm sure I'll do it at some point.
either way, unless you get some heavy stainless steel caps or something crazy like that, smooth caps should help.

[JanGeo]

I noticed the water spray out of the rear wheel well of other cars on Tuesday highway trip and it seems that a lot of spray comes off the top of the tire blowing forward and then out of the top of the wheel well. That has got to be wasting power. I think a layer of clear shrink wrap over my hubcaps will have some effect - need to find a wide piece - I think I have some from a laser toner cartridge shipment that should be wide enough - pop off the caps wrap and pop them back on.

[cfg83]

I have had the snap-in baby moons. They are gorgeous but they fly off in a good bump (always my front passenger rim, maybe it's a front wheel drive physics thing particular to my previous Saturn coupe). The "real" baby moons that you see on hot rods are screwed onto the wheel rim.

How about the "floating hubcaps" that are on Taxis? I have a bunch of URLs but none of them look exactly like the ones I have seen in Los Angeles. Also, it doesn't look they are offered retail. You need to buy them in mass. Finally, they are not "flush", there is a gap between the tire rim and the floating hubcap, or the circumference is slotted, so I don't know if that negates the benefits of the flat hubcap (the ones in LA do look cool, though).

http://www.adcaps.com.au/pages/about.html
http://www.visiononwheels.com/Hubcap/Hubcaps-Taxi-Advertising.htm
http://www.hubads.com/products/abs.htm
http://www.adcapscanada.com/html/gallery.php
http://www.media-wheels.fr/ (in French)
http://www.tradekey.com/selloffer_listall/uid/254727/D-DAM-Advertising.htm
http://www.alibaba.com/member/autopure/product.html

[zpiloto]

I have had the snap-in baby moons. They are gorgeous but they fly off in a good bump (always my front passenger rim, maybe it's a front wheel drive physics thing particular to my previous Saturn coupe). The "real" baby moons that you see on hot rods are screwed onto the wheel rim.

How about the "floating hubcaps" that are on Taxis? I have a bunch of URLs but none of them look exactly like the ones I have seen in Los Angeles. Also, it doesn't look they are offered retail. You need to buy them in mass. Finally, they are not "flush", there is a gap between the tire rim and the floating hubcap, or the circumference is slotted, so I don't know if that negates the benefits of the flat hubcap (the ones in LA do look cool, though).

http://www.adcaps.com.au/pages/about.html
http://www.visiononwheels.com/Hubcap/Hubcaps-Taxi-Advertising.htm
http://www.hubads.com/products/abs.htm
http://www.adcapscanada.com/html/gallery.php
http://www.media-wheels.fr/ (in French)
http://www.tradekey.com/selloffer_listall/uid/254727/D-DAM-Advertising.htm
http://www.alibaba.com/member/autopure/product.html

You could put the GS logo on there.:D

[kickflipjr]

Floating hubcaps the "anti-spinner"

What WILL they think of next?

[WisJim]

I have a set of "Moon" discs (full wheel spun aluminum, snap on type) on our 2000 Metro, and it looks really cool!! The only disadvantage that I see is that you have to remove the hubcaps to check tire pressure.

[MetroMPG]

Or you could drill a 1/2 in hole and use a valve extension. That's what I did after I streamlined my stock wheel covers.

[ketel0ne]

I have had the snap-in baby moons. They are gorgeous but they fly off in a good bump (always my front passenger rim, maybe it's a front wheel drive physics thing particular to my previous Saturn coupe). The "real" baby moons that you see on hot rods are screwed onto the wheel rim.

How about the "floating hubcaps" that are on Taxis? I have a bunch of URLs but none of them look exactly like the ones I have seen in Los Angeles. Also, it doesn't look they are offered retail. You need to buy them in mass. Finally, they are not "flush", there is a gap between the tire rim and the floating hubcap, or the circumference is slotted, so I don't know if that negates the benefits of the flat hubcap (the ones in LA do look cool, though).

http://www.adcaps.com.au/pages/about.html
http://www.visiononwheels.com/Hubcap/Hubcaps-Taxi-Advertising.htm
http://www.hubads.com/products/abs.htm
http://www.adcapscanada.com/html/gallery.php
http://www.media-wheels.fr/ (in French)
http://www.tradekey.com/selloffer_listall/uid/254727/D-DAM-Advertising.htm
http://www.alibaba.com/member/autopure/product.html

$350 for a set of 4 before the artwork.

Feel free to take the following idea and trick out your ride.

Mount 4 10" LCD's wired to a dvd player to them, or led's in changing light and color patterns. The ideas are endless :).

[ketel0ne]

http://cripedistributing.com/images/images_big/81131-41.jpg

http://cripedistributing.com/stainless-hubcaps-8113041-pieces-p-391.html

14" $18.00/4

http://cripedistributing.com/stainless-hubcaps-8113141-pieces-p-390.html

15" $30.00/4

[cfg83]

http://cripedistributing.com/images/images_big/81131-41.jpg

http://cripedistributing.com/stainless-hubcaps-8113041-pieces-p-391.html

14" $18.00/4

http://cripedistributing.com/stainless-hubcaps-8113141-pieces-p-390.html

15" $30.00/4

I still can't believe how good this price is. You're getting four rims for the price of one. I am so depressed. When I traded my coupe for my wagon, I should have had the dealer switch the wheels. My (scratched) alloys are not compatible with my (covered in dust) wheel covers.

CarloSW2

[ketel0ne]

They came today, put them on tonight, drove around the neighborhood. They squeek a bit and each one fits just a bit weirder than the one before. I may need to buy another set, something tells me 1 or 2 of these are gonna come off. But they are exactly the same as the $80 and $100 sets.

[lindermant]

pics K-1, pics!

any chance you can adjust the inner "fingers" to get a bit more hold on the caps? It's all fun-n-games until you realize you've only got three hubcaps instead of four :D

[ketel0ne]

pics K-1, pics!

any chance you can adjust the inner "fingers" to get a bit more hold on the caps? It's all fun-n-games until you realize you've only got three hubcaps instead of four :D

I stretched em out a bit, ill see if i can make the whole commute in the morning and then check them, it got dark shortly after I put them on.

[Wazabi Owner]

I got my 13" discs for my Metro tonight as well. Haven't driven it yet to see/hear the squeeks. I doubt I could hear it over the alternator belt anyway, it's making a racket. Looks cool though. :) I wish I would of paid $18-$30 for them. I am gonna be mad if I lose one.

[JanGeo]

Any chance they squeek because the grab the outer edge of the rim instead of in deeper?

[ketel0ne]

I think it may just be the metal teeth on the metal rim. I may run a ring of 2 sided grip tape around the rim where the teeth grip.

[cfg83]

I think it may just be the metal teeth on the metal rim. I may run a ring of 2 sided grip tape around the rim where the teeth grip.

That's what it is. I tried duct tape on the teeth, but nothing got rid of the noise on my coupe.

CarloSW2

[DracoFelis]

I think it may just be the metal teeth on the metal rim.
Hmmm...

I wonder if it would help to paint a little "Plasti Dip" (paint on rubber coating) on the grip teeth? I know that rubber is flexible (so shouldn't be a problem with the movement of the teeth), and also tends to grip (non-slip) a little better than metal. So maybe it would be useful to cut down on the noise?

Edit: Fix typo in product name.

[ketel0ne]

Well, made it all the way in. With the windows up never heard them, 3 of them you need the lug/pry bar to pop them off the left rear you can get off by hand, still working on that one. Pictures later today, have gotten some stares and comments in the garage. Lead to more of is that a hybrid. :)

[JanGeo]

I'm thinking that something is flexing and making the squeeking noise - says something about plastic hubcaps doesn't it. Plastic dip would be a good idea as well as cleaning the rims. Anyone notice any FE improvement with the caps and have photos of them on the car? Would like to try a 15" set on my not so aero 7 spoke mag caps on my xB that surely must be pumping air around like crazy.

[ketel0ne]

http://www.gassavers.org/garage_images/h6upbg5m4ksyrhqlkvar.jpg

A picture is worth a thousand words.

[JanGeo]

Yaaaaa Maaaannnn! sweet!

[cfg83]

Wow, that's a cool Yaris. If you have $100 lying around doing nothing, you could get them powder coated like I did oh so many years ago on my SC2 (RIP) :

http://home.earthlink.net/~cfg83/gassavers/sc2_1997.jpg

Prediction : Within 4 months you will see a few more cars with racing disks in your neighborhood.

CarloSW2

[ZugyNA]

Baby moons cover the center 1/2 or so....full moons cover completely.

[lindermant]

http://www.gassavers.org/garage_images/h6upbg5m4ksyrhqlkvar.jpg

A picture is worth a thousand words.

sweet!

[Coyote X]

Anyone seen anything for a 12 inch rim? The prices on that site are good enough I am considering buying the 12 inch trim rings and some 14 inch moons and gluing them together and trimming the excess off the 14 inchers to fit them. If I am careful they won't look home made :)

[lindermant]

coyote X - mooneyes makes 'em in 12", but they're not cheap...

http://www.mooneyesusa.com/catalog/product_info.php?cPath=188_52_119&products_id=474&osCsid=56dd731a0158dfdc8001452b337e0368

[JanGeo]

Ya should of grabbed my 12" Geo hubcaps - disks with vents - they were too small for my xB 15"

[ketel0ne]

Now that I have them I really would like flat discs instead. :)

[JanGeo]

Need a top or front view to see how curved they are.

[Wazabi Owner]

Here's a horrible picture (low res) and the car is dirty but I just got my discs too. They don't sqeek and they stay on tight (knock on wood). Doubt it'll be too much of a difference in FE, plus I'm still working out bugs on the car so I don't have too much of a decent baseline.

http://www.gassavers.org/garage_images/3pjneg4nvvv5giyw05ao.jpg

[kickflipjr]

The wheels look good on both ketel's and wasabi's car.

[JanGeo]

yeah they do . . . I wonder how they would look black?

[Wazabi Owner]

I've read in several other threads (this one too) about the hubcaps flying off. Well, it has been 2 weeks I've had my caps on and I've still got them - knock on wood :D . I live on a dirt road way out in the country that has some serious washboard and they haven't even wanted to partially come loose. Overall, I've very happy. Can't say if it made a difference for mileage but it sets it apart from all the other Metros.

[Matt Timion]

I've read in several other threads (this one too) about the hubcaps flying off. Well, it has been 2 weeks I've had my caps on and I've still got them - knock on wood :D . I live on a dirt road way out in the country that has some serious washboard and they haven't even wanted to partially come loose. Overall, I've very happy. Can't say if it made a difference for mileage but it sets it apart from all the other Metros.

At the very least, I'm sure it makes your car easier to find in the parking lot :)

[ketel0ne]

At the very least, I'm sure it makes your car easier to find in the parking lot :)

Yeah its the little blue car with people touching it, pointing at it, and other similar activities.

[Coyote X]

http://www.teamswift.net/album_pic.php?pic_id=9863

I made mine out of the 14 inch stainless stell hubcaps (http://cripedistributing.com/stainless-hubcaps-8113041-pieces-p-391.html) from cripe distributing and the 12 inch trim rings (http://cripedistributing.com/chrome-hubcaps-trim-rings-8118242-p-1616.html). Took about 2 hours to cut and fit them together. I only had one made when the sun started going down so I put it on the car and got this shot of it. I will get more pics tomorrow with all 4 on it if the weather is clear. It looks real good for hubcaps that cost me about $50.

[basjoos]

I made mine from 14" pizza pans from Wal-mart, painted white to match the color of my car and mounted with 3 screws and lock-washers (drilled and tapped holes into the wheel), so there is no chance of them departing the vehicle on a bumpy road. They cost me all of $12 for the set of 4.

[Headshot Zod]

This is about two years old. Its a 15" disc on a 16" rim with a trim ring. In order for me to get 16"discs I need to get the ones that attach with dzus fasteners.


http://img165.imageshack.us/img165/4355/moondiscms2.jpg

I used to have them on my 1977 Dodge Monaco Police Car. If I can find any pics I'll scan them in and post. They would be about 16 years old.

[The Toecutter]

Now that I see them, those mudgaurds got to be a huge source of drag... Any need for them?

[Ted Hart]

I'm thinking that something is flexing and making the squeeking noise - says something about plastic hubcaps doesn't it. Plastic dip would be a good idea as well as cleaning the rims. Anyone notice any FE improvement with the caps and have photos of them on the car? Would like to try a 15" set on my not so aero 7 spoke mag caps on my xB that surely must be pumping air around like crazy.

Ever consider a thin bead of RTV before popping them in? Let 'em sit a while before driving ; they pry off (don't use too much!) when necessary ... flats, rotate, etc. My '86 Vette looked so cool with aero wheels! No squeeks, either.

[Wazabi Owner]

Thanks Coyote X for the Cripe 14" discs. I bought two sets for my motorhome I just picked up a few weeks ago (only need one set but they were too cheap to pass up). Should look good as it's a GasSaver type motorhome - it's a Toyota.

[kps]

So, I now have a set of the Cripes disks. The next problem is to attach them to alloy wheels without damaging the wheels -- which I'm sure I can figure out -- and with reasonable access to the valves -- which so far has me stumped. Any ideas?

[zpiloto]

So, I now have a set of the Cripes disks. The next problem is to attach them to alloy wheels without damaging the wheels -- which I'm sure I can figure out -- and with reasonable access to the valves -- which so far has me stumped. Any ideas?

Here's a guy that did it with a Prius (http://priuschat.com/index.php?showtopic=17996&hl=hubcaps). Don't believe the numbers but he has a faily detailed look at it.

[kickflipjr]

This is what one guy on the prius forum said.

I did a mileage test and they added 0.5 to 1.24 mpg in five runs.


I believe these numbers.

[kps]

Velcro?

I don't think that would hold. I use disk magnets for the quasi-baby-moons on my steel wheels (see garage) and lose one every month or two.

[OdieTurbo]

I made mine from 14" pizza pans from Wal-mart, painted white to match the color of my car and mounted with 3 screws and lock-washers (drilled and tapped holes into the wheel), so there is no chance of them departing the vehicle on a bumpy road. They cost me all of $12 for the set of 4.

Could you show some close-ups? I'm pretty handy mechanically and sure I can do this. Cheaper than the damn moons and won't fall off!

I'd like to know what you did for centering, length of screws, etc. I'm sure I can find the pizza pans :)

[DracoFelis]

Thanks Coyote X for the Cripe 14" discs. I bought two sets for my motorhome I just picked up a few weeks ago (only need one set but they were too cheap to pass up).
And since I started this thread, I figured it was finally about time I should pick up some of those Cripe 14" disks. Like you, I only needed one set (in this case for my CRX), but since they are so cheap I ordered a 2nd set so I would have some spares (if I either lose a disk, or one is damaged).

Once they arrive, I expect I'll probably have to drill a small hole in them, so that I can have access to my valve stem (especially the visual marker I have on my stem, that lets me know when my air pressure is low). And I imagine they might stay on better, if I paint a little paint on rubber (which is easy to buy in a hardware store for a few bucks a small bottle) on the spring loaded teeth that hold them in place. But otherwise, I expect them to be pretty easy to put on. And I'll even get back some of the extra hubcap weight, as I intend to remove the existing OEM "center caps" from the wheel, before installing these new hubcaps. So the only "extra weight" will be the difference in weight between the new hubcaps, and the wheel center caps I'll be removing!

BTW: The forum post about the Prius owner (that someone else linked to in this thread) probably does put smooth hubcaps in perspective (as an aerodynamic mod). After all, around 1 MPG for a 50+ MPG car, is around a 2% gain from the hubcaps. i.e. enough to be "worth while", but small enough that it would be easy to miss the benefit unless you already have a high MPG car. And I wouldn't be surprised at all if that number is about right. However, either way, I suspect my car will look a little nicer with the hubcaps on, even if I don't get a (small but) noticeable FE boost.

[OdieTurbo]

Found a great article on do-it-yourself moons!

Main site is http://www.vfaq.net/
Actual article is here: http://www.vfaq.net/mods/Hubcaps.html

Very neat application of pizza pans! Think I might try this myself!

[cfg83]

OdieTurbo -

Found a great article on do-it-yourself moons!

Main site is http://www.vfaq.net/
Actual article is here: http://www.vfaq.net/mods/Hubcaps.html

Very neat application of pizza pans! Think I might try this myself!

Many I wish I had seen that years ago. Very clean design. Must look cool on the freeway too. I wish I didn't have alloys.

CarloSW2

[MetroMPG]

I'd drill & tap alloys to put smooth covers on - if I had alloys.

If only my VX rims had fit my Firefly. If only....

http://images6.theimagehosting.com/albums/24809/firefly-1-vx-rims.th.jpg (http://server6.theimagehosting.com/image.php?img=firefly-1-vx-rims.jpg&album=24809)

(Photoshop job)

Alloys sure look nice, but I'd still cover them up.

[cfg83]

MetroMPG -

I'd drill & tap alloys to put smooth covers on - if I had alloys.

If only my VX rims had fit my Firefly. If only....

...[Cool picture of Metro + VX rims]...

(Photoshop job)

Alloys sure look nice, but I'd still cover them up.

I really don't like alloys to begin with. I like the ability to change "the look" of the wheels, and alloys just leave you stuck with someone else's design. I'll add it to the todo list. My alloys are pretty scuffed up, so it's not like they are worth much for resale.

CarloSW2