Driving Conservatively

My first car was actually a full sized pickup truck. I was 15 years old when I acquired my hardship driver's license. The challenge, in a pickup truck, is keeping something in the gas tank. Turns out the truck made 11 miles per gallon, at best. Having very little income at that time, I was keenly aware of how much I was spending at the gas pump. I did everything possible to decrease my gasoline expenses.

One thing I noticed when riding with others was the intensity and frequency of acceleration and deceleration during a trip. Different drivers have different habits. Some are we what you call "heavy footed", or in some cases, "lead footed"; when the light turns green, they put the pedal to the metal. What we need to consider is that vehicles are "momentum machines". In other words, the work of a vehicle is done by increasing momentum.

Yes, a vehicle expends energy when it is cruising, climbing a mountain, countering wind resistance and even when it's just sitting idle. But for most of us, driving in a city, a vehicle will use most of it's energy just accelerating after a stop. Your commute or trip to the grocery store is a series of starts, stops and turns. On an open highway, most of your energy expended will be fighting wind resistance. If you want to cut down on gasoline usage, your goal is to reduce the amount of acceleration required. There are different strategies in the city than on a wide open highway.

In the city, the best thing you can do is learn what speed you need to acquire. Obviously, you don't want to break any speed limits, which are there for the safety of yourself and others. But there are times we should stay under speed limits. Take for instance two intersections in a row in which you either must stop or you might need to stop. Depending on the distance between these two stop signs, you just need enough acceleration to get you from the first intersection to the next within a reasonable amount of time. If you "gun it", you might shave off a second or two from your trip, but you'll use much more fuel than necessary if this is your practice.

So, how much is too much acceleration? If you are having to hit the brakes and leave tread on the road before every stop, you are accelerating too much. Honestly, if you can see your next stop coming up, just let off the gas. If you are using the brakes a lot, you are using too much gas. Every time you hit the brakes you are throwing momentum away. Remember, your car is doing work when adding momentum. If you take momementum away by using your brakes excessively, it's like pouring gas on the road. So, learn to judge how much momentum you need to make it to the next stop sign or traffic signal. Once I get the general feel of how long it takes for a certain light to change from red to green, I often try to accelerate just enough so that I make the next green light WITHOUT applying brakes. If you are approaching a red light, let off the gas rather than braking just before the intersection. Once you've accelerated enough, take your foot off the gas and coast a bit before applying brakes. A coasting car is your friend. Coasting is like free transportation. The more you coast, the more gas you save.

On the highway, the same principles apply. You want to apply as little gas as possible. If you have a manual transmission, you want to be cruising in the highest gear so that the motor does not need to turn as much. Some automatic transmissions have a "drive" and an "overdrive" gear. You can disable overdrive by putting the vehicle in plain ol' "drive". Disabling overdrive gives you more immediate acceleration at top speeds, but your motor is turning faster, again using more fuel.

Aside from the gear you use, coasting is still your friend on the highway. You might see a blockage coming up on the highway. What to do? Let off the gas. Let the wind and friction of the road slow you down before applying brakes. Same thing goes if you know you are approaching your exit: cut the gas. There's no need to keep top speeds if you're only going to hit the brakes very soon.

Coasting also helps reduce wear and tear on your brakes. Rapid starts and stops mean a brake job sooner than later. I've never paid less for a brake job than I expected. Why be in a rush to return to the mechanic again?

Most of all, be safe and observe the traffic laws. You won't save any time or money by paying fines in court. Worse yet, an auto accident could potentially eat your life savings, even with liability insurance. If you'll slow your driving habits down a skosh, you'll reduce your risk of an accident, a moving violation, fuel expenses and mechanical repairs.

Happy driving!