Traveling in truck's wake to boost MPG?
 

While driving on an interstate, how far behind an 18-wheeler should I safely travel in order to reap the MPG benefits of traveling in the truck's wake? Is the resultant MPG boost worth taking the time to do this, or is it negligible?

I remember seeing something like this 'tested' on Mythbusters. The conclusion, if I am not mistaken, was that you only benefitted significantly if you were about a metre from the back of the truck—you save on fuel, but lose out on life expectancy. Above that distance, the effects are almost imperceptible.

(I add that when on my scooter, there is a definite benefit even at a safe distance. I think it's the more upright profile compared to a car, as well as the greatly decreased weight.)

The closer you will go to the truck, the better MPG you will get over time. You still have to use your own judgement though...

@ I remember seeing something like this 'tested' on Mythbusters

... Actually their conclusion was that you could still get a (small) drafting effect at a safe distance. Additionally, if you are very close, you end up braking & accelerating more frequently in order to maintain a static distance & hence start using more fuel.

Stay an absolute minimum of 2 seconds behind ... OK you're not gaining a lot, but you do gain a little (which is better than having to spend $$$ on repairs).

I can't tell the exact benefit, because I have no fuel consumption display, but I experienced that it helps a bit (on a motorcycle it does, at least). Even from the safe 2+ second distance.

It's not worth it to get closer, though. Just like MMUK wrote, it's not "only" dangerous, you'll begin to follow the changes in the truck's speed with braking, so you'll end up losing what you had just gained.

Even safe distance drafting can have this effect under unfavorable conditions, so I don't recommend it except for motorways and other detail-less main roads. Otherwise it's better to be independent :)

I often get behind the truckers on the highway. I obey the "2 second rule" and notice only a couple extra mpgs (on average) over 50 miles of travel.

Thanks everyone. I'll try it next time I'm on my bi-weekly 300-mile round-trip. I figure, if I can do this consistently (and it works), I'll save $48 to $72 a year. (That would just about pay for the exhaust-pipe patch I just had done!)

I am a truck driver and I'm all about saving money but before u get on a truckers *** to try to say 80 bucks in over a years time. Have someone follow u so closly that u can not even see them and know how it feels. If u work in a factory and have ur superviser standing on ur ***. That's how it feels

That's one of the reasons why you should stay at least 2 seconds back (as pretty much everyone has agreed in this thread).

I've got video of a moped rider about a metre or two behind a heavy goods vehicle (travelling at 60mph). Insane.

As a million mile+ driver I recommend staying as far as possible away from large trucks.An "alligator" thrown up can easily take out your windshield.BTW if you can't see his mirrors he can't see you.