tire air diflector MPG gain?

[GasSavers_BEEF]

that is why you get flat (or nearly flat) hub caps. check out racing disks or moon disks on a google search.

the gains aren't usually worth the expense but they look cool

[collegekid01]

I like the idea of angling them out to deflect the air around the outside of the car

[Daveedo]

Originally Posted by BEEF

that is why you get flat (or nearly flat) hub caps. check out racing disks or moon disks on a google search.

the gains aren't usually worth the expense but they look cool

Like whats on insights?



Also, for a design for the deflector take a look at what the solar race cars do. I'm thinking of the flat space type looking solar one that you can barely even see the tires on. I'll go try to find a link to a pic.

http://www.msnbc.msn.com/id/8728002

[DRW]

Hey! you have a pic of my car
I didn't see this thread earlier. Here's the thread where I show the details of installing my tire fairings. gassavers.org/showthread.php?t=2381
Unfortunately I haven't recorded any solid gains with these since I was making a few other changes at the same time. I'm sure it's only a small gain anyway.

[GasSavers_BEEF]

daveedo,

more like this


the moon disk doesn't allow the air to churn around in the spokes of the rim. they are expensive but they do have a very distinct look.

you are thinking about fender skirts like on the back of the old insights (the new one doesn't have them) but I figure you won't see too many gains from that either or they wouldn't have scratched that item off of the new design.

[collegekid01]

ahhh! i love the idea about the solar car. so from the top looking down the tire would have a tear drop shape around it. There would be a front and back piece to this deflector type. I think it can be done

oh and just because they took it off a production car doesn't mean it doesn't help much. It could just be that people thought it looked ugly. I know I did, but who cares what your car looks like if you get awesome mpg out of it!

[Daveedo]

I went to Western WA U and never saw hide nor hair of the solar car they were so proud of. Sorta a bummer but I am a scientist and not an engineer so I guess I didn't qualify .
back to the issue at hand...I'm guessing that the double teardrop style of tire airdams that the solar car uses is for a good aerodynamic reason. Wish I could find info to confirm that though.

[GasSavers_BEEF]

if you look at BASJOOS (a member here) he has made his car into a tear drop shape. he made a boat tail on the back of it which makes it much more aerodynamic. he claims that his cd (coefficient drag) is 0.17 which I believe to be true but I don't know how he tested it.

he is getting really good mileage. check the top 10 cars, his is "keeps on rollin'". I know that there are other factors involved in his mileage but the cd of most cars is around 0.35 give or take.

tear drop shape is aerodynamic. distance jump skiers also use a tapered or tear drop shape on their outfits to cut through the air better. they have them on their legs. if you were to take a cross section of the leg, it would be tear drop shaped.

sorry, went out on a tangent but check out basjoos and his car keeps on rollin' it is worth a look. you may be able to message him about aero. he knows a lot about it.

[trautotuning]

I have tire deflectors as well. Front and back.

Like I have mentioned it before, there is not other Mazda6 getting as high of gas mileage as I am; and until someone comes around beating me and doesn't have tire deflectors is when I will take them off.

[GasSavers_theCase]

I took a 540 mile round trip one day when the weather was moderate snow (5 inches or so). Aside from the slow driving, watching the cops work the accidents, and generally crappy conditions, I noticed something else. Natural tire air deflectors!

I'm sure others have seen in snowy regions how the snow builds up in front of and behind the tires forming a wedge of snow that I would assume forms in areas of "dead" airflow. Three observations from this;

1. both the leading and trailing snow defectors are tapered , I'm guessing a 60 degree angle?
2. The snow follows the curve of the tire. down maybe 4 inches or so.
3. The snow is much closer to the tire than the wheel well, maybe only an inch or so away.

Conclusions:

1. Tire air defectors might benefit from following the curve of the tire.
2. Such deflectors could extend beyond the edge of the wheel well.

In hindsight I wish I took some pictures, but alas, it was just too cold, dark and miserable to take any. I don't plan on making any deflectors, but it was interesting to note how the natural world works sometimes.

Oh, yeah, my mileage was in the mid 30's for the trip, same trip in the summer I'll get 40+ depending greatly on the prevailing winds. I guess one could conclude from this that air deflectors decrease mileage.