TRANSLOGIC 71 only scratches the surface of the MPG-obsessed driving activity known as hypermiling. People all around the world are looking for ways to save on gas, but hypermilers take it a step further by employing extreme, sometimes controversial, techniques to squeeze every last drop of energy from their fuel tanks.
Our introduction to hypermiling tries to keep things simple, but even some of our "10 Commandments" are up for debate. Head to any online hypermiling resource and you'll discover that discourse and disagreement are common among this community. Some fuel saving practices are called into question out of concern for safety, while others vary slightly from car to car and transmission to transmission.
For instance, Commandment 2: turning off your air conditioning does increase gas mileage--that's a fact--however, rolling down your windows can negatively impact your vehicle's drag coefficient, especially at higher speeds. There's a tipping point at which keeping your windows up to improve aerodynamics may actually result in better gas mileage than turning your AC off completely with the windows cracked. But, with so many variables like speed, exterior temperature and wind conditions, it's hard to know when that tipping point might come into play for your particular vehicle.
Another hotly debated topic is Commandment 3. Should you or shouldn't you shift into neutral when coasting down a hill? It really depends on the length and grade of the hill, the type of transmission you have (not just manual vs automatic, but also how advanced your automatic trans is), and the speed you need to travel. Your engine uses very little gas when idling in neutral, whereas, when coasting in gear, it is possible to use virtually no gas while above a certain RPM. However, in some instances coasting in gear will also cause you to slow down gradually due to resistance in the gearbox. That's not a problem if you're coasting to a stop sign at the end of the street, but if you need to maintain a certain speed along a lengthy hill descent, neutral may be the only way to do so without engaging the throttle.
The most important consideration while hypermiling is safety. In neutral, for instance, you have less control over your vehicle, which is dangerous if you need to make a quick evasive maneuver. Same goes for Commandment 6. Drafting, or tailgating another vehicle closely enough to gain aerodynamic benefits from their jetstream, is entirely unsafe, often illegal, and should not be done.
Now you're familiar with some of the general principles of hypermiling, but that's really just the start. Trial, analysis, debate and controversy are in some ways as much a part of this passionate community as the goal of fuel savings itself. With so many factors, it's hard to always know who's right, but you can never go wrong by making safety your first and foremost consideration while driving.
Click the image below to watch TRANSLOGIC 71: Commandments Of Hypermiling: