When drivers set out to hypermile, there is a spectrum of techniques that they can use. These range from the good - don't blast away from a red light and don't speed up then slam on the brakes at the next red - to the risky. Dale Earnhardt, Jr. may be able to use hypermiling tricks like shutting down the engine at high speeds to win a race, but that doesn't mean you should try it during your commute.

The AAA thinks we need a reminder to not risk our lives - or endanger others - in order to save a little bit of gasoline. Drafting, coasting and "rolling through stop signs and driving at erratic and unsafe speeds" are specifically mentioned in the group's official statement on dangerous hypermiling (read it after the jump).

Who's performing these techniques? It's hard to say, but we can assume that the AAA knows a thing or two that we don't. After all, they're out there rescuing the increasing number of people who are running out of gas these days.

[Source: AAA]

Warning: Don't try this! The safest distance to drive behind a big rig at 55 miles per hour is 150 feet. Driving any closer is insane because it puts you in the driver's blind spot and also does not give you enough time to respond if the big rig's driver changes speed. This post is for informational purposes only.

Drafting is a technique, usually used by race cars, to reduce drag by driving closely behind another car. Mythbusters did an episode about Big Rig myths that included a look at the drafting... myth? Does anyone really consider drafting a myth? Anyway, they found drafting increases your miles per gallon up to 39 percent at 10 feet distance away from a big rig. At two feet apart however, they found miles per gallon actually went down.

The first part of debunking the drafting myth took the Mythbusters team to small wind tunnel to prove putting things in front of other things blocks wind. Good thing, too. I know I've always questioned stories of objects blocking the wind and can only be convinced by a wind tunnel experiment. Sarcasm aside, while the episode was dangerous and 39 percent is kinda shocking, Mythbusters should not have done this!

No one thinks drafting is a myth and the information they gathered only encourage people to try this. What's next for Mythbusters; how much will over-inflating your tires increase your mileage? How much fuel can you save by turning off your engine at high speeds? How many engine parts can you remove and still drive your car? Mythbusters did warn that driving so close to a big rig is insane but doing tests that find the drafting sweet spot looks like encouragement to me.

[Source: Mythbusters]

Avid hyper-milers and NASCAR drivers already know that following closely in the slipstream of another vehicle can reduce the amount of energy it takes to maintain a given speed. Drafting is a known phenomenon but researchers in India wanted quantify how much of an impact it really has. At Jadavpur University they put four cars into a wind tunnel and found that the second car in the series would need twelve percent less fuel to maintain 50 mph and the third and fourth cars needed twenty-one percent less fuel.

They don't say how close the cars were too each other but it was likely a lot tighter than would be prudent on public roads with unknown drivers. The only way this might be practical in the real world is when cars are equipped with vehicle to vehicle and vehicle to infrastructure communications to preemptively warn of potential problems. Even then there are far too many variables such as road conditions, different drivers and other obstacles to make such close following a viable practice.

[Source: AutoExpress]