tire air diflector MPG gain?

[collegekid01]

Has anyone got solid numbers on a gain from using the mod where a bent piece of plastic deflects the airflow around the tires? I'm thinking about doing some of those with some ABS plastic I have left over from this semesters projects. (I'm an Industrial Design Student and have access to lots of cool goodies)

[Daveedo]

Got any pics or links to what you are planning?

I recall when i was investigating building an EV that deep dish rims were said to be pretty bad for aerodynamics and some guys would make flat wheel covers for their rims. (sorta like big flat hubcaps)

[collegekid01]

yeah
or more like

[GasSavers_BEEF]

like using mud flaps for the front of a tire. I have extended my airdam which has some similar issues to deal with.

you will have som scrub when you are going over speed bumps and also when going over different terrains. I suggest you use a material that gives some and isn't too rigid. also, make sure that it isn't long enough to get caught between the tire and the ground as to get ripped off. I can't see that being good regardless.

good luck with the experiment. also remember, you can always redo it if you aren't happy with the results of the first one. I used a trash can for my airdam and used some tin snips to cut it up. that gave me a pretty thick piece of plastic/rubber (about an eighth of an inch) and the trash can was only about 15 bucks. for you, there would be plenty left over if you wanted to use it for other projects.

[collegekid01]

yeah, I have an air dam but would like to try something like this in the front as an addition to the air dam and in the back as well.

[winkosmosis]

Wouldn't you want it to be curved or angled, rather than straight like a mudflap? I bet the tire is more aerodynamic than the flat flap.

[Snax]

Well I think that as an appendage in front of the tire, unless you can manage to produce a clean airflow up to the flap, it essentially works as a spoiler, in which case it forms it's own pressure bubble ahead of it. (A sort of virtual cowl.)

I honestly can't guess how much effect these things have, but they are on allot of cars shaped primarily as a basic flap. But that's not necessarily proof of the concept over a more rounded shape. Perhaps it get's the majority of the same effect however, even if not 100%.

[Improbcat]

Originally Posted by winkosmosis

Wouldn't you want it to be curved or angled, rather than straight like a mudflap? I bet the tire is more aerodynamic than the flat flap.

The problem is not the aerodynamics of the tire, it is the massive amount of air the tire is swirling around it as it rotates. When air flowing towards the tire encounters this turbulent air it creates a aerodynamic mess with air moving in all directions and mucking up the aerodynamics all around that area. Deflecting the air around the tire keeps the air flowing towards the tire, and the air swirling around the tire more separate keeping one from messing with the other.

[aalb1]

Originally Posted by Improbcat

The problem is not the aerodynamics of the tire, it is the massive amount of air the tire is swirling around it as it rotates. When air flowing towards the tire encounters this turbulent air it creates a aerodynamic mess with air moving in all directions and mucking up the aerodynamics all around that area. Deflecting the air around the tire keeps the air flowing towards the tire, and the air swirling around the tire more separate keeping one from messing with the other.

Great explanation... These make a lot of sense now.

[winkosmosis]

Originally Posted by Improbcat

The problem is not the aerodynamics of the tire, it is the massive amount of air the tire is swirling around it as it rotates. When air flowing towards the tire encounters this turbulent air it creates a aerodynamic mess with air moving in all directions and mucking up the aerodynamics all around that area. Deflecting the air around the tire keeps the air flowing towards the tire, and the air swirling around the tire more separate keeping one from messing with the other.

Gotcha.

Would most of the spinning air be at the spokes? How about making a deflector angled outward, so air gets deflected outward and away from the spokes?