Heuer Autavia Ref. 2446/C

Here we have a beautiful Heuer Autavia in stunning condition. Three sub-dials in reversed panda color scheme, a striking red seconds hand, cream-colored lume on faceted hour markers. What’s not to love?

But the trained eye might spot something unusual…a rotatable tachymeter bezel. Wait, what?

As you might know, a tachymeter bezel can be used in cooperation with a chronograph to read how many times a certain event potentially occurs in an hour. Simply put, if you measure the time it takes to race one mile, the tachymeter bezel will show you how many miles per hour you have been driving on average.

So why would you want to have that scale rotatable? It is actually Heuer’s simple solution to allow you to time multiple consecutive events, which would otherwise require an expensive and complicated fly-back or split-time chronograph. It does take some training to use effectively though.

The idea is you start the chronograph when you set off. When you pass the first kilometer or mile indicator, you quickly read where the chronograph seconds hand is pointing. Say, for example, you see the hand passing  the 36 seconds mark as you pass your distance indicator, you memorize that number. Next, you read the associated number on the tachymeter bezel, which would indicate 100 kph or mph. Lastly, you turn the bezel so that the triangle now points at the 36 seconds marker. This will allow you to time your second mile or kilometer without ever stopping the chronograph.

Got it? Now try it with driving gloves on while blasting down a race track! Ok, perhaps this is better suited to the navigator rather than the driver.