There are many things you can do to improve your fuel economy. Some of them, such as driving a more fuel efficient car, are obvious. Other options, such as changing the route of your commute, are less obvious, but just as beneficial.
The way you drive your vehicle has a major impact on your fuel economy. Driving your car with the intent of saving fuel can result in 10-20% better fuel economy.
What kind of driving saves fuel?
At speeds above 60-65 MPH, most of your fuel is used to overcome wind resistance. The wind noise you hear when you are driving down the highway is the sound of your vehicle pushing its way through the air. All of that pushing takes a lot of fuel. The faster you go, the more difficult it is to overcome the air resistance, and the more fuel it takes.
The easiest way to fix this fuel wasting problem is to keep your vehicle below 60MPH. Keeping your vehicle below this speed will significantly reduce the amount of fuel you burn trying to overcome wind resistance.
In some cases you will have no choice but to exceed 60MPH. In these cases it’s best to still try to drive as slowly as you can within reason. This will not be the fastest way to get to your destination, but it will use the least amount of fuel.
While staying below 60MPH reduces your aerodynamic drag, going really slow isn’t good either.
Stop-and-go driving is the worst for fuel economy. When a vehicle is rated on efficiency for “city driving” what they are actually meaning is stop-and-go driving. It’s called city MPG because most cities are setup in grids with stop signs or traffic lights at the end of every block. Starting and stopping over and over is terrible on a car, and it will return the worst fuel economy you can get. Any time you apply the brakes you are using up energy that was put into the car with the brakes. That is energy that would have continued to push the car forward without any additional fuel.
Objects at rest tend to stay at rest. A stopped vehicle is a lot harder to get up to speed than a vehicle that is already moving. Starting a car from a dead stop is the least fuel efficient thing you can do. If you’ve wasted all of the fuel that it takes to get a vehicle up to speed, and then you use the brakes to come to a complete stop again, that will get you terrible MPG in anything other than an electric vehicle.
Consistent cruising is ideal.
What you’re shooting for is steady cruising. You want to be in your highest gear with the engine at the lowest RPMs. This will probably be somewhere between 45-60MPH. It depends on your specific vehicle where this range will lie. You want to accelerate slowly from a stop just until you shift into your highest gear. This is easy to determine in a manual car, but can be also easy to see in an automatic if you watch the tachometer. Once you reach this speed, you want to do everything you can to stay right there. You don’t want to go much faster because that will increase your wind resistance and RPM. You don’t want to go slower because that will be a gear down and result in higher RPMs (and fuel usage) at less speed. Once you’re in the sweet spot you want to look ahead and try to avoid situations that would require you to speed up, or apply the brakes. The ideal situation is one where you can maintain this ideal speed for the entire length of your trip.
The perfect route
For most trips, maintaining the ideal speed throughout will not be possible. We all have that one light that we all catch, or that turn where we have to sit and wait. What is advised though is to plan out you most traveled routes to minimize stops. Most people will only have one or two frequently traveled routes. Work, school, and grocery store are most likely the top three most traveled routes. Look at each one of these routes and determine if there is an alternate route that would result in fewer stops. Adding a couple minutes to the drive isn’t as bad on your fuel economy as making additional stops is. If there is a route you can take that would result in three less stops, but it adds 5mins to your trip, it’s most likely worth it.
How do I know what route saves the most?
Monitor your fuel usage. Reset your trip odometer when you fill your tank. Take your normal route to work and back every day until you need to fill up again. When you fill up, write down how much fuel it took to fill up and how many miles you traveled. Divide the miles traveled by the gallons used and you’ll know what your average MPG for that tank was. Now, reset your trip odometer again, and for this tank try out a new route. Keep driving the new route until you need to fill up again. This time when you calculate your fuel economy for the last tank, you’ll know if your new route took less or more fuel than your normal route.
Keeping track of your fuel usage in this way will allow you to determine the optimum fuel saving routes for most of your daily driving chores.