I was driving home down the M25 yesterday and got tucked up behind a big artic and I noticed I was getting a 'tow' from the lorry.....when I pulled out to overtake I noticed the extra bit of throttle I needed

Was this my imagination? I know that I'd have had to get through some turbulent air from the 'bow wave' of the lorry but I am sure that when I was tucked up close behind I was getting 'dragged' along??

 

Yep, slipstream - you've got to be pretty (dangerously) close though.

 

Have you never seen Days of Thunder Zero?

You obviously work too hard.

Del.

 

you should know all about slipstream given your boy racer characteristics zero

 

I was wondering where the 'hole' would be? i.e where all the turbulent air would be located that might actually hinder you

The traffic was so heavy last night I must have been only a car length away from his rear end

yeah I am boy racer.....!!!! it's why no passenger will ever come out with me........hell though what are the side windows for if not to look out of??

 

If we ever convoy, you can go in front.

 

It's actually the turbulent air that helps you. Basically, rather than flowing in a laminar fashion past the vehicle, it forms vortices behind it instead. You feel buffetted because rather than blowing straight at you, the vortices are blowing this way and that, and it's this lack of direction from the air that reduces the air resistance, and hence you go faster with less right foot.

The size of the hole is dependent on the size and speed of the vehicle. It's also helped by lorries that have the down to the ground 'skirts'. I could (but can't be bothered) drag out my aeronautics course notes to get a rough idea how big, but to be honest, the only proper way is a wind tunnel without monster computing power.

 

Air resistance represents the most significant force acting on a car at over 30mph

 

You should try riding a pedal bike and tucking in behind a lorry. A friend of mine got done for this. He was doing 45mph.

 

nice on Ade!!