[Eden Auto]

Eden Auto  asked the Naked Scientists:

Good day,

Picture this - a vehicle travelling at a fair speed along a freeway - It creates a high-pressure pocket in front of it and a low-pressure pocket behind it.

So, when a vehicle (e.g. your car) follows another (e.g. large truck) closely at speed, the vehicle at the back, to some extent, gets dragged along and uses less fuel while it is following. (No pushing that frontal cushion of air out of the way all the time).

With some of the modern vehicles that show you an immediate computerised fuel consumption readout, you can observe this very noticeable change in fuel consumption of the rear vehicle, as well as noting the position of it's accelerator for that speed.

My question - Does the vehicle in front have to use more fuel at this time, (or, possibly, less fuel as that 'low-pressure pocket' behind the front vehicle is being filled somewhat by the vehicle at the back)?
 
Thank you,
Ken Harwood - Germiston, South Africa

What do you think?

[syhprum]

Vehicles traveling in close proximity can be regarded aerodynamically as one with a reduced fuel consumption or greater top speed for both than they would have separately.
I earlier times when competition was not so cut throat race drivers working as a team used to use this technique