How close does one need to drive behind another vehicle to get in their "draft" to save gas?

Question

Not that I would do this, because it is not safe. But I was curious. What's the distance at 60MPH? at 70MPH? Behind a truck? behind a van? behind a sedan? And how much gas would one save?

Answer 1

Benefits -

1 or 2 miles per gallon more

Risks -

Not being able to see hazards or debris on the road in front

Not being able to react in time if vehicle in front brakes suddenly

Getting hit by debris kicked up by vehicle in front

Getting flagged by police for 'following too close' or 'aggressive driving'

Best option

Same speed at several hundred feet following distance

Answer 2

Not enough. Race cars do that  because ever one it going the same high rate of speed. And the car bodies create the draft due to their design. On the high ways you are not going fast enough nor is your car designed to get  you any more mileage that way

Answer 3

The money saved by tailgating like this will go for your wheelchair van when you are crippled by doing this. IT IS NOT WORTH IT!

Answer 4

very close its not worth it.  Plus drafting is most effective at very high speeds.

Answer 5

i read its 10 ft. if you're doing drifting an 18 wheeler. I think the article i read about this said you get %20 better milage due to less wind resistance.

so, id say its not worth it at all.

Answer 6

If you are within 20 feet you will save about 40 percent and with that 40 percent you save you will likely be killed, it is very unsafe to do this.