[johnunit]

as for drafting vs. tailgating:

I've followed a truck long enough in the Prius to notice a clear efficiency difference (10+% at the same speed, similar weather, etc. on the same trip), and ended up at the same gas station as the truck I was drafting. I identified myself as the owner of the green Prius that had been behind him for most of the last hour or so, and said I was trying to find a sweet spot between making him uncomfortable and not benefitting from his wake. He said he'd been quite ok with me being behind him, and said something about preferring my behind him at the same speed as him vs. people coming up on his butt on the hills.

As plenty of other people have said in this thread and elsewhere:
There is absolutely a distance where you can follow MOST trucks in MOST situations where you are not annoying the trucker but are gaining worthwhile efficiency.

While I'm not good about keeping fuel logs, I've also noticed what seems to be better mileage while safely drafting large trucks in my much wider, less aerodynamic, more powerful 85 Ford Crown Victoria. "Safely" in this case meaning I was comfortable and could not discern any annoyance from the trucker.


There are some people on here who seem to have downright reckless (at least on any road near me) driving techniques. Personally I would absolutely NOT use pulse and glide on any major highway. Varying your speed to that degree, especially if you're letting it dip much below the speed limit, will throw even many attentive drivers off. It's also worth noting that if you're getting marginally better fuel economy in your already efficient car at the expense of encouraging or even forcing (in the case of a difficult passing manouever) heavy foots in gas guzzlers, you may be doing more harm than good. Ie. pissing off an SUV driver every quarter mile and making them slow down then floor it to get around you might save YOU a couple cents per mile of gas, but he's burning 15 cents to get around your slowpoke but. Laugh at him all you want, but he's drinking from the same trough as you and he likely would have kept a steady speed if it weren't for you.

Put more simply: A 2 lane (each way) road with one guy doing 55 and 49 cars doing 75 is likely consuming more more gas than a road of 50 cars doing 75. It might be largely due to the stupidity of those other 49 cars, but it's still gas usage and it's still something with you as the root cause.