I know slipstreaming / "drafting" is somewhat frowned a pon, and for some good reasons. However, especially with a smaller car, being in the wake of a larger vehicle dramatically reduces drag. In windy situations it can make all the difference when trying to cruse at a set speed. Please note, I mean at a safe distance, not tailgating. Thoughts?
When possible ( not often ) I try to "surf" in the wake of a semi-trailer by being in the adjacent lane ( preferably on the truck driver's side ) and about even with the back of the trailer. This way , I can get a nice tug from the trailer that might be an additional 10 MPG and still be safe. There may be an official term for this maneuver ? Don't know. But it works.
The down side of drafting other than the inherent safety issue of being too close to the vehicle in front of you is the damage done to the front of your car at speed. Those trailer tires are throwing pretty much everything they roll over up in the air. If you're sitting behind it under say four or five second back that material is going to impact the front of the car. I tested the distance back that I could still be in the draft, even at three seconds behind the trailer I was still benefiting. At that distance running 65 mph I could still hear small road debris impacting the windshield. My question is, a new windshield, a front end and hood paint job or even an AC condenser worth the .50 a gallon you are saving drafting?
I'm with Al. I don't drive behind anything for any length of time if I can help it (and I almost always can). I like my life and, frankly, I like my car. Instead I just cruise at the PSL. 99% of the time that means I'm getting "good" fuel economy (as far as my thirsty ride is concerned) while all the rolling road hazards cruise on by.
There are some benefits with slipstreaming, but, most of the time are not worth the effort... I have found some in long highway drives with very specific kind of rigs that are going at my speed ( depends on which car I'm driving ) and road and traffic conditions are good enough for me to give it a shot. On short drives, the benefit will be so small that it is not worth the time and effort...
Only time I decided it was worth it was driving I-80 from Laramie to Rock Springs Wyoming. With pretty much continuous 45 mph head winds it was better just to tuck behind trucks lumbering along at 55 fighting the same wind.
I've gotten noticeable benefits from following large trucks at a safe distance. The largest benefits were when the truck was going slower than I felt comfortable doing on my own. So I could tuck in behind them, and anyone coming up behind us could see that I was not the person "holding up the line". The truck, after all, is a lot more visible than the MINI. So they'd go around with a lot less fuss, and I could cruise at ~5 MPH lower than my "typical" cruising speed without worries. That was good for ~15 MPG if I recall correctly! -soD
That's also true. The combination of lower speed and lower wind resistance adds up to quite a difference in FE.
Good plan, IF you can find such a truck. In my experience, large trucks steadily doing less than 65 mph or so on Interstates for more than a short distance are pretty rare.
