Side mirror drag & effect on fuel economy - quantified

[PaleMelanesian]

All I'll say is, don't go accusing me / us of claiming things we never did. Trying to add to discussion by bringing in something we both heard/read. I never said I knew this to be a fact.

I AM willing to entertain the possibility that mirror removal is not an automatic absolute improvement. Take the example of vortex generators. By adding turbulence and drag in one place, they can reduce drag somewhere else. Could mirrors help in that same way sometimes?

[Frank Lee]

Commonly accepted, based on what?

[MetroMPG]

Could it have been mentioned in the Hot Rod (?) article about the Camaro drag reducing mods? For some reason that keeps coming to mind.

[cfg83]

Frank -

Originally Posted by Frank Lee

Kind of like Carl's quote, if there's anything I've learned over the years, it's that there's a lot in aerodynamics that is counter-intuitive.

D'oh!

CarloSW2

[i_am_socket]

Just to resurrect this thread... I was going over the list of general aero mods and was looking at the side mirror deletion and came across this thread. Looked up the NJ motor vehicle equipment laws and it states that 2 external rear facing mirrors are required.

Boo.

The one's on Skeeter aren't too bad, but I might possibly like to find something smaller that's equally as effective... Similar to the 5th Gen Civic's. The extra ~2mpg could be worth it.

[trikkonceptz]

The expensive way around your law would be to remove the mirror and install back up cameras in there place with 4" screens inside the car. The camera could be molded into the flat panel to give the most aerodynamic shape and therefore serve both purposes.

Unless the law states the mirrors have to be glass, the cameras would technically act as mirrors and improve blindspot visibility because of their often 180 degree range ..

I have seen simple back up camera setups for as little as $30 retail and I am sure you can get them on the cheap via ebay ...

[MetroMPG]

I'm sure this has been mentioned before, but the potential drawback of cameras for mirrors is they may not do as well as mirrors at night.

[Bearleener]

Good point on the night vision of cameras.

Someone mentioned flow spreaders. Some BMWs seemed to have these in the form of longitudinal ridges on the top surface of the mirror housing. They seem to have gotten away from those recently, though.

I'm leery of deleting even the passenger-side mirror; it's saved my butt on several occasions.

FrankLee is right that we can't always assume an improvement. The test pilot Scott Crossfield mentioned that there was once an airplane that had less drag with the landing gear *down* than up!

How about boattailing the mirror with a clear plastic cone? Has someone tried or seen something about this? Is the clarity sufficient at night?

[i_am_socket]

Been doing a lot of eBay searching today

I looked it up and it doesn't specify glass, just rear facing; could be a great option. I have visions of finding a pair of motorized side view mirrors to cannibalize so I can use the stock position control, take out the useless tweeters in the door corners and put small (< 3" if possible) screens there, and mount the cameras (which are pretty darn cheap and tiny) behind semi-tinted plexi to keep them stealthy.

I haven't been this excited over a mod project since my first homebuilt PC

*edit*
RE: night vision of cameras
As long as I can see headlights and relative location of vehicles at night, its good enough for me. Dark is relative in my area: the light pollution is visible from space.

[MetroMPG]

Originally Posted by Bearleener

I'm leery of deleting even the passenger-side mirror; it's saved my butt on several occasions.

Nobody should do something they're not 100% comfortable with, but don't forget to visit your local auto parts store - there are some large moderately convex mirrors that can work well on the inside of the glass in the same line of sight as your original mirrors.

A mirror deletion doesn't necessarily mean no mirror at all.