Hey, sorry to bring up an old(er) topic but I have been doing some extensive research regarding side mirrors and the legalities behind them. I've noticed a wide range of laws and regulations for various states within the U.S. which made me wonder what federal regulations were regarding those aero-killers (well, perhaps aero-infirmers
) since obviously federal standards trump state and local regulations unless the state/local ones are more stringent. Here is what I have come up with:
571.111
The "basics":
1) All cars must have an inside rearview mirror that is not convex, provides a 20 degree horizontal viewing angle, and a view of a flat road surface (not greater than 61 meters past the rear of the vehicle) vertically to the horizon.
2)
All cars must have an outside driver side mirror that is not convex, and "shall provide the driver a view of a level road surface extending to the horizon from a line, perpendicular to a longitudinal plane tangent to the driver's side of the vehicle at the widest point, extending 2.4 m out from the tangent plane 10.7 m behind the driver's eyes..." EDIT: That creates an angle of view of approximately 12.5 degrees. See the attachment for a quick visual I drew up.
3) An outside passenger mirror is only required if the inside rearview mirror is insufficient in providing an adequate field of view outlined in item #1. That means most if not all trucks with campers, vans, or other such vehicles legally require a passenger mirror.
Read the full regulation for more info; there's a lot of interesting stuff in there. I hope this helps anyone who wants to or already has modified their mirrors and wishes to stay within the law.
How's that for a first post
