- 1). Make sure your tire pressure is correct. A major reason for excessive fuel consumption is because there is a problem with your vehicle's tires. Check your tire pressure weekly by using a tire pressure gauge. There is a chart on the back of the front driver's-side door that says the exact tire pressure specifications. The owner's manual says to keep the front tires at 29 pounds per square inch, or PSI, and the rear tires at 26 psi. However, each Malibu model may have a different specification, so to be exact you must check your vehicle's chart. If your tire pressure is lower than it should be, make sure to put more air in your tires. Make sure you have the correct size tires on your vehicle. The tire size for a 1998 Malibu is P215/60R15.
- 2). Keep your vehicle properly maintained. Routine maintenance and tune ups will keep your fuel consumption from becoming higher than it should be. Some things in particular that can affect your mileage are engine oil, spark plugs, fuel filter and air filter. The engine oil in a 1998 Malibu should be changed every 3,000 miles. The air filter and fuel filter should be changed every 30,000 miles. The spark plugs should be checked at least every 30,000 miles but do not need to be replaced unless they are worn.
- 3). Keep the fuel injection system clean. An easy way to help keep your fuel injection system clean is to regularly use fuel injector cleaner. Different brands of fuel injector cleaner will have different intervals between use.
- 4). Make sure you do not have a fuel leak. Because a 1998 Malibu is an older vehicle, there is a higher risk that you may develop a leak somewhere in the fuel system. Check the fuel lines, as well as any connections within the fuel system, to make sure there are no leaks.
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