How close do you have to follow behind a semi-truck to effectively "draft"?

Question

Trying to save some money on gas.

Answer 1

just don't do it stay back enough so you can see the trucks mirrors and out of his blind spots but if you insist on tailgating a truck you can get a ticket for following too closely on the bright side you will save alot of gas when you get killed in the crash

Answer 2

It's people who try these things that give a bad name to truck drivers.  If you can't afford gas prices then take the bus or buy a hybrid.  You're not only risking your life in this stupid stunt but you're risking the life of the trucker and EVERYONE else that is close to a truck.  Want to be responsible for 100 lives because you caused a 50 car pile up because you tailgated a hazardous goods truck filled with concentrated acid or sulphur?  

There's other ways in saving money at the pump.  Go slower.  Don't gun it at green lights.  Don't idle for no reason.  Keep your engine clean-regular maintenance.  Tune ups.  Learn to do this yourself to save labour money.  Don't buy gas guzzlers.

Answer 3

google "mythbusters drafting"...they covered it on one of their shows. If I recall, you have to be so insanely close its absolutely unsafe and stupid.

Answer 4

when ur bumpers are "kissing" and ur airbag has gone off.  u have got to be kiddin.

Answer 5

If I was you I'd just follow at a safe distance. Whatever you and your brakes feel comfortable with.

Answer 6

You could not get close enough to draft, besides that is a good way to get killed, I think your life is worth more than a gallon of gas, don't you?

Answer 7

about one foot or so....mythbusters tried it and confirmed....

Answer 8

There are  better ways to save gas that one will kill  you

Answer 9

I remember reading an article on this before, but I can't recall the actual distance they concluded on. But I do remember them saying that while in theory this would work, the distance was so small that the risks caused by the impaired vision, far outweigh the benefits in gas mileage.