Maxing out your miles per gallon

Any recent fill-up at the gas station has probably left you with a queasy sense of panic. With fuel prices at an all-time high, it’s especially hard for commuters and rural Alaskans to stomach the expense. Fortunately, you can fight back with some common sense strategies for improving the gas mileage of your car or truck.

One of the most over looked means of improving your gas mileage is maintaining proper air pressure in your tires. Low tire pressure can decrease your mileage by as much as 2 to 5 mpg or more. Assuming your vehicle gets 17 mpg, you could increase you mileage by 40 to 100 miles based on a 20-gallon gas tank. That is a savings of $10 to $25 per tank.

Tire pressure will naturally decrease over time. Pressure should be checked every time you fill up and a tire pressure gauge is a small, but wise, investment. It is also a good idea to keep a mileage log. A sudden decrease in mileage is important to note because it may indicate a mechanical problem, like low tire pressure.

A typical recommended tire pressure is about 32 psi, but this can vary up or down depending upon your vehicle make and the kind of tires it uses. If you are unsure, check with your owner’s manual, mechanic or tire manufacturer. Most automobiles state the recommended tire pressure on a metal plate on the frame of the driver’s side door.

Some people are trying to improve their gas mileage by over-inflating their tires to reduce resistance. They are correct in their reasoning that this will increase their mileage. Over time, the practice of over-inflating your tires is much more costly than the gasoline it saves. Over-inflated tires wear down much more quickly than properly inflated tires and they have greatly reduced breaking efficiency.

If you use over-sized tires on your truck or car, consider dropping back to the manufacturer recommended tire size. While large tires look cool and provide an added measure of traction, the hit to your pocketbook is likely profound. Reducing tire size can increase your mileage by as much as 5 mpg or more.

Another overlooked fuel waster is your air filter. A dirty air filter can greatly reduce fuel mileage. Most automakers recommend a check of the air filter every time your oil is changed (every 3,000 to 6,000 miles). If you live on a dirt road or frequently drive in dusty conditions (like windborne glacial moraine dust), you may want to increase this interval.

Automobiles built since the early 1980s don’t need the same kind of tune-ups that once ensured peak mileage, but they are still not immune to the ravages of time, mileage and nature. Check with your auto dealer or mechanic to find out when belts, spark plugs, plug wires, etc. should be replaced on schedule. While it is tempting to ignore these items until a problem occurs, an up-front investment will pay off handsomely down the road.

Believe it or not, using your air conditioner during warm weather rather than rolling the windows down may increase your gas mileage. The aerodynamic drag caused by open windows on some vehicles is greater than the drag the air conditioner compressor places on the engine. The only way to know for sure is to calculate your gas mileage every time you fill up and use a log.

Improving your driving behavior can also have a positive impact on your gas gauge. Accelerating slowly from stops and driving the speed limit will increase your mileage and decrease the likelihood of unwanted encounters with law enforcement officials. Planning your trips can be one of the best ways to reduce your fuel costs. Can you combine two or three trips into one?

Finally, are you carrying a lot of unneeded weight in your car or truck? It is not uncommon for many Alaskans to carry their work tools and other items wherever they go. This makes sense on the homestead or jobsite, but do those tools and other dead weight really need to go with you to town?

Stephen Brown is an agriculture agent for the Mat-Su District.