zelio
Elio Addict
Thank you, Paolo, for that exposé on wheel shrouds/fenders/mudguards. It is a lot more interesting than this weeks Tech Talk and the last two weeks blogs from Elio Motors. I laughed when I read some of it and I am still smiling. I think the responses are going to be "ve-ry in-ter-es-ting". LOL ZRecently following this thread, I implore that all the aesthetic enthusiasts engage in open minded thinking about exposed wheels.
Tonight's post is an open eyed view of the 'fender' debate, which considers the pros and cons of running an open wheeled vehicle to the currently proposed shrouded wheel of the Elio P4. I offer that reasons for covering the wheels are tenfold to the reasons to leave them uncovered. In that light, observe the following:
Top Ten Reasons for Elio Wheels Shields*
10. Additional surface area to place advertising.
9. Place to put bumper stickers that can actually be read by passing motorists that say things like "Me and 80+ mpg" or "Do not sit on wheel covers'.
8. Expands physical appearance and presence of the otherwise narrow vehicle.
7. Offers potential to place LEDs or other lighting effects to enhance appearance or safety.
6. Prevents massive rain-spray cloud from forming in wet driving conditions (think of the common SUV) and dousing windscreen, particularly when turning.
5. Prevents debris or mud-spray from pelting or showering the vehicle, particularly when turning (this can ruin a paint job very quickly).
4. Reduces exterior noise of the wheels in the same way air and turbulence are reduced.
3. Eliminates potential 'climbing' of adjacent vehicle that might drift into your lane, thereby increasing safety.
2. Emits the Elio coolness or uniqueness factor while needlessly driving around your neighborhood to show off your awesome new ride.
1. Reduces aerodynamic drag by a factor of 2 or more, thus attaining the 84 mpg target.
Top Ten Reasons to run open wheel or P2 or P3 style stubby 'fenders':
1. Personal preference for styling (as in expected or accustomed appearance).
Sorry, there really is no other rational reason other than 'looks'.
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* Terminology:
US: Fender - Short for Defender (old school)
British: Guard - Short for Mudguard (old school)
Tech: Shroud or Shield - better technical description of the Elio P4 wheel cover
('wheel shields' has greater poetic effect).
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For tech support on reason #1, do your own research. A couple of suggested sites are:
http://www.gmecca.com/byorc/dtipsaerodynamics.html
http://www.motorsport.com/automotive/news/irl-open-wheel-car-aerodynamics/
http://www2.hesston.edu/Physics/PhysicsRacing/researchpaper.htm’
The take-away of all this is that the coefficient of drag "Cd" dramatically increases with the increasing exposure of the rotating wheel to the point that an open wheel vehicle will more than double the drag experienced by a closed wheel vehicle. The Cd will literally increase from 0.30 or less to 0.50, 0.60 or more. One simple quote: "The biggest sources of drag on an open wheel car like an Indy car are the wheels. ...the wheels account for about 60% of the total drag." (DBN477 presented some goo info – thanks.)
This means that if you remove the Elio wheel shrouds, your highway mileage will drop to that of a common Honda Civic or worse, given the intentionally relatively low power of the Elio engine. Think of the Elio as a system or an organism. It all works together and is more than just the sum of its parts. Synergy. This is how Paul Elio thinks. I am sure he is very cognizant of R. Buckminster Fuller and the Dymaxion project. (read about Bucky if you have time.)
Now, if you will excuse me, it is 5:10am and I am going back to bed. :-)