Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Side mirrors

Love the comments on the side mirrors. The real question is why are we using mirrors. The laws specifying mirrors were written before small video cameras. We spend lots of gas pushing those large mirrors through the air. I propose that we change one word in the law.

Change “mirror” to “device”. Let’s give the design engineers more freedom.

Prof. Bill

‘‘devices’’ malfunction.
Mirrors don’t.

Once the “device” fails then a aftermarket side mirror from your favorite auto store will need to be screwed to the side of the car with no remote adjustment.

I had to install an aftermarket side mirror on an old Toyota and I hated it! It always had to be adjusted and it required both of us to adjust it.
‘Devices’ and fancy engineering drive up the cost of a car. Mirrors are fine the way they are now and I’d sooner pay for a dependable car that doesn’t burn oil, has good gas mileage, and is reasonably priced! I never buy ‘NEW’, cars that are proven are the best!

Just consider the gas needed to push all those drogue chutes through the air.

I do agree that simpler is better, but in this case maybe not. A system with no blind spots and decreased aerodynamic drag would save millions of gallons of gas as well as being safer.

I propose we get the regulators out of the design process and see what happens to future cars.

I’m glad someone is readings this. Thanks for the comments.


Interesting idea, though I wonder…where do you look to see what’s in the “mirror”? Mirrors are easily visible without taking your eyes very much off the road. Are we to look at the nav screen in the dash when we want to change lanes, or will the display be projected to our line of sight onto the windshield?

Sure the technology is available to do this, but how many people want or need it? Sometimes you can have a prime rib dinner when all you need is a decent burger.

decreased aerodynamic drag would save millions of gallons of gas

I certainly agree that external side mirrors are an obstruction in the airflow which increases drag and surely does diminish fuel mileage. But by how much? Would the difference be significant? That’s a tantalizing question.

I’m not a skeptic, just intrigued by your proposition. So I’ll respectfully ask if your statement is based on what seems likely and obvious to all of us, or is there some experimental data that you have and can share which quantifies the benefit of eliminating side mirrors. It would be interesting to know how significant the fuel savings would be. If it hasn’t yet been researched, that might be a worthwhile subject to investigate. It seems this would be extremely easy research: Drive, measure mileage, remove mirrors, repeat drive cycle.

For those interested in other research being done on automobile fuel efficiency, look at work done by the Rocky Mountain Institute, They’ve developed a non-steel replacement for auto body components for radical weight reduction yielding much greater fuel efficiency. If I recall correctly, I think I even saw Tom and Ray do some demonstration with the material. Here’s what RMI reports on their website:

Making cars lighter is the single most effective and widely impactful lever by which to dramatically and immediately improve their fuel efficiency, regardless of vehicle type, size, fuel, or powertrain technology.

For more info,

RMI has published a fascinating, detailed (and at times very technical and thus hard to digest) book on energy efficiency for transportation, electricity, buildings, and industry: It’s titled: “Reinventing Fire”. I’ve worked through parts of it, but it’s not a quick read. Info on the book is on their website. I found it at my local library.

Is there a definitive study on the cost to gas mileage due to side view mirrors? If so what is the estimated loss in mpg? I would think it minimal.

" I would think it minimal. "
My outside mirrors are bullet shaped and pretty "slippery."
What if research showed that they actually improved MPG by spoiling some drag, eh ?

" . . . .millions of gallons of gas " [?]

" . . . .millions of gallons of gas " [?]

I’d better re-vacuum my floor mats and take the maps out of the glove compartment.


no, bad idea.
Just as not all motion is forward, not all technology is good.
The more complicated the plumbing, the easier it is to clog the pipes.

Compounding mirrors into periscopes that view to the left and right of the interior mirror might be much easier to view and might allow some improvement in the aerodynamics of the outside mirror and would certainly be much cheaper and more reliable than tv monitors. I drove a vehicle with a blind spot warning system and it seems such a device leads drivers to rely on such gimmicks and trust them too completely. Somewhat like electronic ABS and traction control, technology often becomes a sky hook to give inexperienced drivers a great deal more confidence than their talents deserve.

Thank you Westernroadtripper. All very good points. I looked at the url from the composite folks. I’m sure that they are most interested in weight. That is why composites exist. Weight is important but not the whole answer. Rolling resistance and mostly aerodynamic drag are also important. I’m not talking about Cd but flat plate. The real number is Cd time S the frontal area. So reducing effective flat plate should be just as important as reducing weight. Quoting Cd is a sales ploy to get us to feel good about driving bigger cars.

Your idea of carrying out experiments are just exactly the next step. If I wasn’t old and retired, I would do it myself. Somebody out there will read this and get it done.

Even a very small reduction in drag will add up to a very large savings in fuel for the nation. I don’t think millions is an bad number, but it is not based on experiment. Someone needs to do that.

High tech is not always good, but it is not always bad either. The regulators need to give it a chance. Some smart young person will put a system in your next car that will have you wondering how you lived with just a side view mirror.

More wild ideas at"


I wanted to say how much I appreciated the tip re: positioning the side mirror to eliminate that nasty blind spot. I can now travel the Garden State Pkwy without having to turn to the left to make sure it was clear. (are some folks thinking, ‘you may want to rethink that!!’) True, it takes a bit of getting used to but thus far its great! I’ve shared the tip with several others. I had to chuckle at the direction of the comments. Obviously, I am out of my league re: car aerodynamics (that line of thought never occurred to me) but since i’m not going to fly I’m happy with repositioning tip.

One of the car magazines, forget which one, wanted to see if they could get a Trans Am with a 455 to hit 200 mph. This was a long time ago so I don’t remember all the details, but they came up just shy of the mark, so they removed the side mirrors and tried again, made it the second time. The difference was very small as I recall, one or two mph, but it did have an effect, maybe.

Because the second run was at a different time of the day, that could have also factored in. removing the side view mirrors for fuel economy sake is about like the argument about front license plates. If we are to sacrifice safety for the sake of fuel economy, then there is about 400 lbs of safety equipment that we could eliminate and that would really help fuel economy.

Another thing about aerodynamic drag, it is an exponential function, not a linear function. At 200 mph, its a huge factor, but at speeds below 45 mph, its pretty insignificant. The electricity needed to power a camera system is a constant and is is also a drag on the system. While it is a low drag when compared to the aerodynamic drag above 45 mph, it is a drag that is there at the lower speeds and even when the vehicle is just idling at a stop light.

One thing no one has considered though, why do the side view mirrors have to be located outside the car? Can they not be mounted on the dash board on either side of the instrument panel? I tried this once after a came back from being stationed in Japan for three years. In Japan, the side view mirrors are mounted on the fender about 6" behind the headlights. It looks ugly but it gives you a commanding view all around your vehicle. You have a 360° view without taking your eyes off the road. You can maneuver in traffic with just inches of space, and in Japan, inches is all you get.

Anyway, I mounted two convex mirrors on the dash that simulated the line of sight to the fender mounted mirrors I had in Japan. It didn’t work quite as well as the fender mounted mirrors and they weren’t pretty as the dash was not designed for this.

If the camera system were to be tried, I’d like to see two cameras mounted the fenders just behind the head lights and the 5x7 images projected onto the windshield via heads up display at position within the line of sight to the cameras so they would have the same effect that the side view mirrors in Japan have.

To clarify, Rocky Mountain Institute is a multi-disciplinary think tank searching for ways to contribute to reaching sustainable energy policy for the planet. Their target is a plausible way to totally replace fossil fuels by substituting renewable energy sources (wind, solar, geothermal, etc). The first step in that proess is dramatic reduction in energy demand in every sector, transportation, buildings, industry, etc, so that the amount of energy necessary to power society would be far far less than currently, and thus easier to achieve with renewables than most people can now imagine.

The composite material for vehicles is just one component of the solution they are developing. Chances are that their prototype vehicle also has multiple aerodynamic advances, possibly including a substitute for external side view mirrors. I’d guess that among other things, it would have a completely enclosed underside as well. You’d enjoy their book, “Reinventing Fire”.


Personally, I’d like to have a 3-part array of screens immediately above or below the upper steering wheel that show views from three bullet cameras providing a full 180 degree view, two on the sides of the front fenders and one in the center rear edge of the roof, along with the flag style rearview mirrors and center rear view mirror currently required.

Outside mirrors can be terrible to use in poor weather, looking through a rained-on side window at night. They can also eaisly get covered with crap on the highway. Cameras would be a real asset in poor weather. Putting the screens right in front of the driver would eliminate the need to take one’s eyes off the road.

Mirrors are, however fine in good weather, and are certainly an asset should you lose the cameras for some reason.

Oops. Vw already did it.

100 miles per hour 280 miles per gallon.

I want one.