I learned this little nugget of wisdom today and I felt the need to pass it on.
The side mirrors on your car are positioned wrong. Sounds basic but it is true. Most of us think that the proper position of our side mirrors is angled to display the flank of our car and the road behind it. However, safety experts say that’s not correct. Studies from The Society of Automotive Engineers (SAE) show that the mirrors should in fact be positioned so that no part of your car appears in them. That’s the best way to negate blind spots that require you to turn your head when changing lanes. The mirror placements should slightly overlap with the field of view in the center-mounted rear-view mirror.
The only problem is getting used to the SAE-recommended mirror positions but it can make a huge difference in terms of safety. The inside rearview mirror should be used to keep an eye on what is coming up from behind, while the outside mirrors reflect the area outside the view of the inside rearview mirror. Make sense? I set mine that way today and, while it was weird for a few hours, it did seem to make perfect sense!
Take a look at this diagram (courtesy of Car & Driver) for more details.