Setting The Exterior Mirrors On Your Car

A Poor Reflection on Fashion

Setting Outside Mirrors to the Correct Angle

By Eddie Wren — Copyright © 2023

Fashion plays a big part in modern life, but it is highly doubtful whether road safety trends should ever be subject to it. Yet there is currently a buzz regarding the settings for exterior mirrors. The recommended method is potentially risky and has no benefits other than the promotion of laziness and the de-emphasis of reasonable care by drivers. No matter how well-intended, this technique should never be sanctioned.

The new method is being promoted in the USA but would apply equally in any country with left-hand-drive vehicles and is reversed for countries with right-hand-drive cars.

Consider the rationale behind the new advice (illustration: ‘Car Two,’ below). It states, for the USA, that when setting the left-hand exterior mirror, a driver should place their head against the glass of the driver’s door window and then align the exterior mirror to show just a thin sliver of the car bodywork. Traditional advice states that the mirror adjustment should be made while seated, usually for driving, not with one’s head against the glass.

Similarly, proponents of the new method say that the driver should lean to the right until their head is central, across the width of the car, before setting the right-hand exterior mirror — again to show just the very edge of the car bodywork. But, once again, the traditionalists state that this adjustment should be made while the driver is generally sitting in the correct driving position.

Those who recommend the new idea of ‘wider’ settings for the wing/exterior mirrors claim that the method reduces the need for a driver to glance over either shoulder and that it also gives a better view through the relevant exterior mirror of cars that are alongside one’s vehicles on a multi-lane highway. They also claim it reduces unnecessary overlap between the views through interior and exterior mirrors (see the striped, green zones in the illustration ‘Car One’ below).


Car One: The ‘traditional’ way of setting the exterior mirrors. Note the lack of red-striped blind spots inside (i.e., below) the thick red lines. The green-striped areas denote the view overlap from the interior and exterior mirrors. 

These settings prevent any other vehicles, including motorcycles, from coming up behind, unseen.

Car Two: Setting the exterior mirrors ‘wide.’ Note the large, red-striped blind spots inside (i.e., below), the thick red lines, and the large areas of green above those same lines.

Depending on how wide a driver sets his exterior mirrors, this technique creates large, un-viewable blind spots that can hide other vehicles, all so that the driver concerned doesn’t feel obliged to do shoulder checks.

The areas above the thick red lines denote zones a driver may view simply by turning their head when appropriate. These diagrams are not to scale — they were created using nothing more complex than the ‘M.S. Paint computer program — but they still clearly show that setting the mirrors ‘wide’ creates two large, dangerous rear blind spots which can not quickly or safely be viewed and that if a driver ever does turn their head — an action that this technique seeks to reduce — it creates even more unnecessary overlap than do the traditional settings.
Illustrations Copyright © Eddie Wren, and ‘Drive and Stay Alive, Inc.’, 2003.

The question is, does this new ‘wide settings’ method do anything at all to enhance safety?
The answer is a resounding ‘No!’ Under several circumstances; it will have the opposite effect.

Before detailing why this is such a wrong method, it is essential to consider those who, through neck injury, ailment, or whatever, have genuine difficulty turning their heads to glance over their shoulders. If this is the case, then one of three things can be done to make life easier and to ensure that the relevant blind spots can still be checked:
— The first is to briefly rock forward, towards the steering wheel, as one looks into the relevant mirror. This gives the same ‘wide’ view as setting the mirror in that position in the first place, and it avoids the driver having to turn to look over their shoulder. Of course, nobody advocates that a driver sits too close or remains too close to the steering wheel when driving, but as long as it is safe to do so at the relevant moment, briefly leaning forwards will not cause problems.
— The second option is to have an additional wing mirror fitted on both sides of the car so that one on each side can be set in the proper, ‘traditional’ manner and the other can be set appropriately broad.
— And the third possibility is to buy small, convex self-adhesive mirrors that can be stuck onto the bottom outer corner of each exterior mirror. These give only a small image for the driver to see but will show whether there is, in fact, another vehicle partially alongside.

There are, however, at least eight reasons why you should not position the exterior mirrors for a ‘wide’ view:

1. Regarding the overlap between interior and exterior mirrors, it is a sad fact of life that most drivers — assuming they use their mirrors at all — only check one mirror when they should be checking at least two. In this case, the question of overlap becomes a moot point and is quite possibly advantageous.

2. A good (meaning ‘attentive’) driver will continuously monitor all of the vehicles coming up behind at all times and, through concentration on the task, will always know what vehicles may be alongside the relevant blind spots. In these circumstances, a shoulder check becomes necessary only to confirm the other vehicle’s exact location or, for example, whether it left the highway at an interchange one has just passed.

3. If exterior mirrors are set ‘wide,’ then on highways, there is a risk that a motorcycle could be hidden from sight in the relevant blind spots, and the rider(s) could be killed if a driver starts a turn or a lane change. On urban roads with slow-moving traffic, there is a similar danger for bicyclists coming past on the right-hand side of one’s vehicle, especially if near an intersection or driveway where the motor vehicle driver is about to turn right.

4. In all except two-seat sports cars and two-seat pick-up trucks, the view through the interior mirror will often be partially blocked by rear-seat head restraints, significantly if such have been correctly adjusted for taller teenage or adult passengers. The heads of any such passengers will, of course, also increase any obstruction to the driver’s view. The view through the interior mirror is often less than perfect, meaning that going directly to the rear through the exterior mirrors becomes much more critical. Again, this facility is lost if the exterior mirrors are set ‘wide.’

5. In longer vehicles, such as 7-seat minivans* and the larger models of SUVs, the exact length of the car usually means that the view via the interior mirror, through the now more distant back window, is much narrower than it is in a shorter car. This means that the statement via the interior mirror covers a smaller angle, and going directly to the rear through the exterior mirrors becomes much more critical. [Glossary note: In some other countries, the U.S.’ mini van’ is known as an MPV or a ‘people carrier.’]

6. If a minivan or an SUV has a double back door (as opposed to a lifting/lowering tailgate), the vertical metalwork between the two back windows creates another, sometimes very significant blind spot, which makes the interior mirror even less effective than in ‘5’, above. So yet again, the view directly to the rear through the exterior mirrors becomes even more critical.


His photograph shows the view through a convex mirror (i.e., wide-angle to the left of the feint, dotted line). Still, it also indicates that the motorcyclist nearest the car would be in a new and deadly blind spot if the mirror had been angled “wide” — see the diagrams above.

Photo courtesy of Volvo, one of the first car makers to fit blind spot warning devices. As they become more commonplace, such systems will create another point in the argument that setting exterior mirrors wide is ill-advised and unnecessary.  

7. If a relatively tall vehicle, such as a minivan, a significant pick-up, or an SUV, is being followed by a low car, such as a sports car, the quiet car may be hidden entirely below the view line of the bigger vehicle’s interior mirror, but traditionally angled exterior mirrors will give a glimpse of it each time it strays out from being directly behind the larger vehicle.

8. The most obvious problem of all relates to reversing. First, a driver must look over their shoulder(s) when doing this. Still, mirrors are usually essential, too — especially in larger vehicles, such as SUVs and vans — so if, for example, a driver is backing into or out of a parking space near a busy mall, how are they to see a pedestrian who walks into the much enlarged blind spots (illustration: Car Two, above) that the ‘wide’ method creates? It cannot be a case of leaning the head to one side to see out of an exterior mirror. That automatically puts the other two mirrors out of alignment while this is happening, and two-thirds of the available mirror view is lost. The only wise method of setting the mirrors so that reversing is always as safe as possible is the traditional method, never the new, comprehensive method.

     [Please remember, when reversing/backing, it is essential to continually check all around — forwards, behind, over both shoulders and in all appropriate mirrors. Reverse slowly so that you have time to do this.]

Craig Steichen, VP of Marketing for Super Concepts, and Q of West Coast Customs (MTV's "Pimp My Ride") stand next to a customized 2005 Ford Escape SUV. (Photo from Ford; February 2005)
Craig Steichen, VP of Marketing for Super Concepts, and Q of West Coast Customs (MTV’s “Pimp My Ride”) stand beside a customized 2005 Ford Escape SUV.
(Photo from Ford; February 2005)

This photograph shows another situation where setting the exterior mirrors “wide” would affect safety.

There is a simple, sensible rule about vehicle windows that are unthinking people often choose to sneer at, and that is: “Keep all windows clean and clear.”

Putting stickers on any window in a car, in a position where they can interfere with a driver’s view, either when looking directly through the window or the interior mirror, is thoughtless and — frankly — stupid. It is in the same category as dangling anything from the interior mirror.

There is no good excuse for doing these things and good safety reasons not to do them.

We will ask a question to counter the inevitable criticism of our opinion. We wonder (for example) how many motorcyclists have died worldwide because a sticker or something hanging from an interior mirror had momentarily veiled their presence when a driver briefly glanced for a view. — If anyone even remotely thinks the answer might be “none, ” sadly, you are very much mistaken.

November 2005.
Another aspect that comes into this argument is tinted windows. Particularly at dusk or dawn or during other periods of poor light, a tinted rear window will significantly reduce the efficacy of the interior mirror. But as the glass in the windshield and the front side windows may not be heavily tinted, the exterior mirrors will not be impaired by the tinted glass — yet another reason to keep them in the traditional position to allow some rearward view at all times.

Except for physically disadvantaged people, as mentioned earlier in this article, why should glancing over one’s shoulder even be seen as a tiresome chore? Pilots in busy flight areas do it constantly, and there is no good or valid reason why drivers should not do likewise on busy roads. Of course, it would be a foolish person who looked over their shoulder for too long or did it at an inopportune moment, but that is not under discussion.

Setting the exterior mirrors of a car by traditional, ‘close’ guidelines is much safer. In addition, it facilitates a better overall rearward view than the modern idea of setting the exterior mirrors ‘wide.’

The writer of this article had the good fortune to be trained as an ‘advanced driver’ and an ‘advanced motorcyclist’ as part of becoming a traffic patrol police officer in Britain — a job which he did for fourteen years. Learning to the U.K.’ police advanced’ standard is an acutely intensive process involving several a hundred hours of training on public roads, among ordinary traffic, often at speeds significantly over iover100mph. It is said by many to be the highest level of public road driver training available anywhere in the world.

While serving as a traffic patrol officer, he specialized in road safety for young drivers and riders, and after leaving the force, he became a qualified (DfT-ADI) driving instructor.

He was later invited to become the managing director of an advanced driver training company established to make training available to ordinary people to take them to the same incredibly high driving standards as British police ‘traffic’ officers (except for the extreme-speed element). During the same period, he became a donor organ transportation driver, often operating at remarkably high speeds where safety was paramount for all the usual reasons plus one extra.

He now lives in the USA, where he founded Drive and Stay Alive, Inc., to help bring the safety message to as many drivers as possible — especially those most at risk, young drivers under 25.