How to Drive Economically

Proper maintenance can help your vehicle function more efficiently. Here are some do-it-yourself maintenance tips to keep your car in top fuel-economy shape.

Know What's Under the Hood

For economy's sake, you should know a little something about what's going on under the hood. Though undeniably complex and computerized, the principles of engine operation haven't changed as much over the years as many believe. Even if you don't do the work yourself, a bit of knowledge goes a long way when communicating with your mechanic and in making sure all the scheduled maintenance gets done.

Read About Your Vehicle

We're not talking manuals with instructions on replacing your transmission. And, for better or worse, modern vehicles don't afford too many do-it-yourself opportunities.

But there are many books, brochures, and videotapes that can help you get some basic insight into the purpose and workings of your vehicle. Examine these materials before you buy, however, and be sure they are aimed at your skill level and are current with the systems on your vehicle.

Don't overlook the automaker's shop manual for your car. Though written primarily with factory-authorized mechanics in mind, it contains plenty of useful information to guide the experienced do-it-yourselfer.

Check and Change the Oil Regularly

Oil is the lifeblood of your vehicle's engine, and maintaining proper oil levels and fresh oil will help keep your engine healthy and operating most efficiently. That leads to gas savings.

Check the level on the dipstick weekly. The oil should be checked with the engine turned off. The best time to get an accurate reading is when the engine is cold and the oil is pooled in the oil pan rather than dispersed throughout the engine's oil passages.

Always use the correct oil viscosity, as outlined in your owner's manual. The viscosity is described as 5W30 or 10W40, for example, and is a measurement of the oil blend's ability to do its job within a particular range of conditions and temperatures.

Using the incorrect viscosity can lower fuel economy by up to 2 percent. Any oil that carries an American Petroleum Institute (API) certification is appropriate. The API also monitors for friction-reducing additives and applies the term "Energy Conserving" to its performance symbol on motor oils that meet this standard.

Some synthetic motor oils are advertised as promoting fuel savings, though the advantage is generally negligible compared to simply changing your oil and filter regularly. Some tests have shown that synthetic oils result in slightly improved fuel economy, though their primary purpose is for use in high-performance engines as part of the total performance package. Synthetic oils are quite a bit more expensive than regular oil.

It's become fashionable to change your engine's oil and oil filter every 3,000 miles. It won't hurt to keep to that schedule, though evidence that it's a bit of overkill is in every owner's manual. Most manufacturers specify 15,000 miles or so between oil changes. They built the engine and should know what it needs to stay in top shape.

Some vehicles even have an oil-life monitor that will announce via a dashboard light when an oil change is necessary. This keeps track of how the vehicle is driven between oil changes and recommends when the oil should be changed.

If the manufacturer's oil-change schedule is outlined in the owner's manual or announced on a dashboard light, we recommend that you follow it.

Change the Air Filter

Some experts say not to expect a huge mileage boost from keeping your engine's air filter fresh; others say a clogged air filter can reduce gas mileage by as much as 10 percent.

In any case, changing an air filter is a simple task you can perform, and a properly operating air filter is essential for keeping the engine clean inside. A clogged or really dirty air filter cuts off air to the engine, and there's no doubt that hurts performance and fuel economy.

Maintain the Cooling System

An engine that runs too cool or too hot may waste 10 to 15 percent of the fuel you put into your gas tank. Your engine's operating temperature is governed primarily by the coolant fluid and the engine's thermostat.

Coolant is a blend of antifreeze and water that helps maintain proper engine temperature in both hot and cold weather conditions. The proper coolant blend is usually a 50-50 mix of antifreeze and water. The level should be maintained as indicated on the underhood reservoir, and the coolant should look clean.

A malfunctioning thermostat might stick open, which lengthens engine warm-up time and lowers the operating temperature, both of which hamper gas mileage. It could also stick in the closed position, which can cause the engine to overheat. Watch your dashboard coolant temperature gauge as a guide. Even if your car has no gauge but a warning light, one way to discover a malfunctioning thermostat is to pay attention to your car's heater. If it isn't delivering warm air within five minutes, even in freezing weather, get that thermostat checked.

Check Belt Tensions

Belts that drive the air conditioner, water pump, and power-steering pump must be tight enough not to slip, but not so tight as to bind. A rule of thumb used to suggest that belts needed a half-inch of slack, but some of today's engines are more delicate. Their belts must be checked by following the manual's instructions exactly, possibly using a measuring instrument to get tension exactly right. In any case, don't forget to shut off the engine before putting your hand anywhere near a belt.

Inspect the Battery

Batteries used to demand water periodically, but most of today's batteries are maintenance-free. What you can still do is inspect the cable terminals for corrosion and cleanliness. That can make the difference between getting an engine to start quickly and wasting gas while the engine cranks over too slowly -- or not at all.

Consider an Engine Block Heater

Motorists in the south may never give a moment's thought to such a device, but people in the north know this one well. Many of their cars have a little telltale plug sticking out of the grille. Connect it to ordinary house current and the crankcase stays warm overnight. Not only does the engine turn more freely in the morning, but it also warms up faster and wastes less fuel during that crucial period.

Pay Attention to the Brakes

Take note of suspicious symptoms. A dragging brake is not only dangerous but can also drag gas mileage down with every rotation. Brake maintenance is best left to an experienced mechanic. However, if you feel comfortable putting a corner of your car on a jack, as though you're changing a tire, give the wheel a spin to see if anything seems to be dragging. If it is, contact your mechanic. And make sure the parking brake is never left engaged when you start the car.

Maintain Wheel Alignment and Tire Balance

Professional equipment is needed to check these, but a misaligned front end or unbalanced tire can rob plenty of mileage. Is the car pulling to the side? Chances are a realignment is needed. Unless front wheels are pointing ahead properly, the tires might scrub against the pavement and steal fuel by straining the engine. Vibration at various road speeds suggests the need for balancing. An unbalanced tire also soaks up excess gas.

Steer Clear of Gimmicks

If there really were a device that could be added to an engine to yield 100 miles per gallon, it would be front-page news.

Gimmicks claiming to boost gas mileage -- a fluid or a gadget of some sort -- pop out of the woodwork whenever fuel supply or fuel costs become an issue. These tend to bear a startling resemblance to the "miracle cures" promised by medical charlatans.

The EPA has evaluated more than 100 such "amazing devices" over the years. A half-dozen produced a "statistically significant increase in fuel economy," and a couple of others did so only by increasing emissions levels. Recall the basic money-saving maxim: If it sounds too good to be true, it is.

Be especially wary of extravagant claims for phenomenal mileage, enhanced power, revived performance, and reduced emissions -- often all at the same time.

In addition to the questionable fuel and oil additives that promise miraculous mileage, many other additives are produced by reputable companies and sold at auto parts stores. Useful? Depends on who you ask.

Some experts steer clear of chemicals completely. Others allow that the occasional can of fuel-injector cleaner in the tank might help keep the injectors clean. Gas-tank additives can also absorb water that comes in with the latest fillup. Neither result has a direct effect on mileage, however. Basically, a car that's filled with high-quality brands of gasoline and oil shouldn't need any additives to keep it running properly.

Proper trip planning can help you use less gas and save some green at the pump. Next, learn about trip planning for energy efficiency.