Wheel disk mod, any MPG gains? before/after?

[s2man]

Originally Posted by elhigh

Quote:
Originally Posted by dremd View Post
How do "moon caps" attach?
Somebody answer me that, please! I'm getting ready to dip into the tax refund and buy some, but I want to know if the attachments are secure enough that my hard-earned dollars don't roll away.

I'm not keen on the screw-on type, either - I don't want to have to go through that much to check my air pressure.

Well, the snap-on's just snap on. Like regular hub caps. Your rim needs to be the type that accepts snap on hub caps though. Are your stock caps snap on? The only time I've ever lost a snap-on was when I hit a pot hole that was so big, it broke my CV joint too.

The screw-on's require you to drill and tap your rims. I was not excited about drilling holes in my rim either. You'll have to deflate the tires to drill right in the edge, beside the bead. And screws can, and have, come loose too.

I thought about attaching pizza pans with toggle bolts, but removing/reattaching them to check the air pressure regularly, sounded like a pain. And clearance between the toggles and the brake calipers would have been tight.

My car had OEM caps held on by the lug nuts. Fortunately, the rims also have a groove for attaching snap-on's. The hubcapsplus.com technician verified snap-on's would work on my rims. They're in the mail.

[MetroMPG]

Originally Posted by tasdrouille

The aero improvement given by those is marginal at best. Unless you're going the DIY route I beleive your money would be better spent elsewhere.

I agree with tasdrouille.

It's going to be a small benefit, likely not big enough to show up above the normal variation in your tank MPG.

It certainly won't hurt, so if you want to do it, do it! But there's lower hanging fruit to be found.

[Chris D.]

Heres another picture of my wheels before I mounted em up..

I'm thinking I could attach something from the backside from those other holes that "look like" universal bolt pattern style (those holes are there to shed weight)

1 or two studs comming out from that position could work..
I could use some a coupler nut or something like that then drill 2 small holes through the pizza pan to attach like that possibly?

I have 16" wheels.. if I could find some 15.5" dia pans, that would sit right inside of the lip causing a flush effect..



I figure any little bit will help and it can't hurt..

That and I love salt flat moon style disks..

[DifferentPointofView]

I really don't like the idea of drilling...

First off, you spend a load on the rims. then, you drill holes in them? Excuse me? I wouldn't buy a new $200 trunk to drill holes in it and save (maybe) a few cents...

[Chris D.]

Originally Posted by Frank Lee

the FE change isn't even gonna register.

So then why are people doing this?

Originally Posted by DifferentPointofView

I really don't like the idea of drilling...

First off, you spend a load on the rims. then, you drill holes in them? Excuse me? I wouldn't buy a new $200 trunk to drill holes in it and save (maybe) a few cents...

I paid 450 for my wheels.. Not very expensive,
but my wheels aren't the type you want to drill into

whats this about a trunk? Don't you have a 4x4 SUV?
save maybe a few cents, but it all adds up to the greater good of mpg and not wasting..

Its a win win brother

[Chris D.]

What? LOL whats that mean? **n00b question activated!**

[cfg83]

Frank and Chris -

Originally Posted by Frank Lee

Means they're using intuition instead of facts in their decisions.

I predict you, like the others before you, will not be able to detect an FE difference from before to after. Then you will tire of the dorky look (depends on how much effort you put into it I suppose; full covers can look good) and pull them off again. Imagine the remorse when you pull the covers off and there's some big ol' screw holes staring back at you from those nice expensive rims.

Make some coroplast covers with valve stem holes (so they can stay put) and velcro 'em on. Pizza pans may require a more substantial attachment.

This is good advice. At least try to prove the mod to yourself, one way or another. I would think that you would need a place where you can "coast down" to a stop (multiple times) without being harassed by the authorities. If I used coroplast on your rims, I would use zipties around the 5 spokes.

If my used SW2 didn't come with alloys, I would have probably installed snap-ins because I like the look. Hmmmm, my alloys came pre-scratched, so maybe there's a pizza pan in their future, !!!!

CarloSW2

[MetroMPG]

Originally Posted by Frank Lee

I predict you, like the others before you, will not be able to detect an FE difference from before to after.

I agree. BUT...

I think it's important to point out that just because you can't discern a difference in tank to tank comparisons, it doesn't mean they don't work. The difference is just likely smaller than the normal variation in your fills.

That's no reason not to do it. There are myriad small aero changes a person could do that are too small to detect individually by watching the fuel gauge, but done together, they likely add up to a measurable change.

Whether smooth wheel covers make a difference depends on the vehicle & wheel style. I'd wager these wheels are on the "bad" end of aerodynamic and worth covering up.

BTW, Frank - have you seen anyone test smooth wheel covers in a somewhat controlled way? (I haven't.)

[NoCO2]

I've had mine for a while and I think they look good, however, I have to agree with Frank Lee, the MPG improvement is unnoticeable. However, they fit nicely with the whole FE mod look. I've also noticed that Honda has started putting almost half-moon disks on their new civic models...so they must be catching on.

[metroschultz]

I neede to buy hubcaps for the Jetta anyway.
I told #1D she was getting a Racing Disc Makeover
Got mine from Amazon, $80 delivered.
I think they use the hubcap guy you called.
I'll post pics when they are installed.
L8R
S.