Ford’s Blind Spot Mirror
As Close As We Can Get To European Aspheric Mirrors
By Kevin Miller
Ford issued a press release this week touting their industry-first Blind Spot Mirror which is being introduced on the 2009 Edge. The Blind Spot Mirror is a traditional side view mirror designed with a secondary convex spotter in the top outer corner, which provides a view of the driver’s blind spot. When traffic enters the driver’s blind spot on either side of the vehicle, it is visible in the secondary convex mirror, alerting the driver of potential danger. It’s a great idea, and a great improvement over traditional driver-side vehicle mirrors.
Ford’s claim of being industry-first is likely true, as this mirror has the convex spotter mirror integrated only into the corner of the mirror glass, and it is the first vehicle in the US to offer such a feature. However, the idea of a rear-view mirror with better visibility is not a new one. I first encountered wide-angle rear-view mirrors in 1998 while renting an Opel Omega in Germany. The Omega had convex mirrors with curved glass along the outside edge of each side view mirror, greatly reducing blind spots around the car.
That same year, Saab introduced such mirrors to the US as standard equipment for the passenger-side mirrors of their 9-3 and 9-5 models. The Saab wide-angle, or aspheric, mirror combines a constant-radius curved area (similar to the conventional convex mirror that is common on passenger side exterior mirrors in the US), with a portion on the outside of the mirror which has a gradually increasing curvature. It is the high curvature in the aspheric area that yields a greatly expanded field of view.
Knowing from my Opel rental experience that such a mirror was available for the driver’s side as well in European markets, I used the then-new Internet and ordered aspheric mirror glass for the driver and passenger sides of my 1995 Saab 900. The improvement in visibility over the stock US mirrors was a revelation. I have done the same for both our Saab 9-5 and our Volvo V70, ordering the replacement mirror glass from European parts suppliers because it is unavailable in the US.
Knowing that mirror specifications (as well as specifications for most other functional automobile parts) are mandated by Federal Motor Vehicle Safety Standards, I did a little bit of research. I found that clause S5.2.1 of FMVSS 111 requires that the driver side of each passenger car shall have an outside mirror of unit magnification. Unit magnification is defined in FMVSS 111 as “a plane or flat mirror with a reflective surface through which the angular height and width of the image of an object is equal to the angular height and width of the object when viewed directly at the same distance .” Basically, this Federal requirement prohibits convex or aspheric mirrors from being installed on the driver side of a passenger car sold in the US. That’s too bad, because it seems to go against the standard’s defined purpose, which is “to reduce the number of deaths and injuries that occur when the driver of a motor vehicle does not have a clear and reasonably unobstructed view to the rear.”
Ford has cleverly found a way around this requirement with the new Blind Spot Mirror, by integrating a second mirror in the corner of the standard, federally-mandated one, all within a continuous glass surface. Presumably, if the mirror glass is heated the convex portion will also be heated, which is never the case with adhesive aftermarket spotter mirrors. Though inferior in function (and field of vision) to the aspheric exterior mirrors available on both sides of vehicles in Europe, it is a great leap forward for drivers in the US who until now have had to put up with flat-glass driver-side mirrors, or add clumsy secondary spotter mirrors.
Ford’s press release, which states the Blind Spot Mirror will be standard equipment on 2009 Edge crossovers, also states that the company intends to offer these mirrors on several upcoming Ford, Lincoln, and Mercury vehicles. That is great news, because better mirrors equate to better visibility, which all of us could use. And until FMVSS 111 is revised to allow aspheric mirrors in the US, Ford’s Blind Spot Mirror is the best mirror available.
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