A while back a friend of mine told me about another friend who owned a Prius. She saw him on 101 in his Prius apparently tailgating an 18 wheeler. When asked about why he would do such a silly thing, he replied that he was trying to maximize his miles per gallon by driving in the draft of the tractor trailer.
How interesting…
Today, I decided to test that theory. I, too, was on 101 on my way to Palo Alto and found a convenient 18 wheeler in the right lane. With a wry smile, I pull up right on his bumper and look at the onboard computer. WOW. It was hovering between 60 and 80 MPG! Amazing what cutting some air drag can do for fuel efficiency. So I ride for a while behind him, and then he cuts left and I notice my MPG drops to 30.
Definitely aerodynamics can make a difference. The Prius is already very aerodynamic, but having another big ass truck cut the air in front of you really helps a lot.
DISCLAIMER: This REALLY a dangerous thing to do. I WOULD NOT RECOMMEND IT ALL. You could drive right up his tailpipe if he jams on the brakes, maybe even die underneath as he crushes your windshield to a pulp (although another friend of mine did remind me that 18 wheelers can’t stop on a dime, so you’d probably have time to brake to a halt even as your 18 wheeled friend was screeching wheels attempting to stop). A cop might just also give you a ticket too.
Don’t be an idiot; perform your aerodynamic science experiments some other way.