The 2000 Pontiac Grand Prix should be fun to drive, equipped with a powerful V-6 engine and sporty styling. Poor gas mileage, however, can cut into the enjoyment of owning and driving this car. The standard Grand Prix, powered by a 3.8-liter engine and an automatic transmission, should be capable of producing 17 miles per gallon in the city and 27 mpg on the highway (See Ref. 1). If your 2000 Grand Prix isn't coming anywhere close to these numbers, there are several components you can check and, if necessary, repair to improve fuel economy.
Limit the amount of weight in your Pontiac Grand Prix. This is perhaps the quickest and easiest fix to help improve your car's gas mileage. If you're carrying unnecessary cargo in the trunk of the Grand Prix, remove it. If you can remove 100 pounds, you may be able to boost gas mileage by 2 percent, according to figures produced by the Federal Trade Commission (See Ref. 2).
Check the plastic valances below the front and rear bumpers of the Grand Prix as well as the skirting on each side of the car. If the valance or skirting is damaged, it will hinder the aerodynamics of the car, reducing fuel economy. If the parts cannot be repaired, replace them by purchasing new or used valances or skirting.
Change the oil in your Grand Prix, replacing the oil with synthetic oil. A quality synthetic will reduce friction within the engine and enable it run more smoothly. With the car's engine running more smoothly and efficiently, you should notice an improvement in the miles per gallon.
Check the Grand Prix's air filter. If the air filter is clogged or dirty, it will diminish the supply of clean air to the engine. Without an adequate supply of clean air, the combustion process within your Grand Prix's engine will be hampered. This, in turn, will limit gas mileage. Replace a dirty filter with a new one.
Check the spark plugs. Spark plugs can often go forgotten for several years. If this is the case, you'll want to pull the plugs and install proper replacements. Spark plugs have a tendency to become caked with carbon, especially if they're left unchanged for years. This leads to poor combustion and decreased gas mileage.
Check the fuel lines, fuel pump and gas tank in your Grand Prix. If the lines, pump or tank have any leaks, it will appear as if your Pontiac is experiencing terrible gas mileage.
Inspect the air pressure in your Grand Prix's tires. Simply use a tire pressure gauge to measure the amount of air in the tires. Then look at the recommended pressure printed on a stamp located on the driver's side door jamb or consult your owner's manual for the correct pressure. If the pressure is low, inflate the Grand Prix's tires. Low tire pressure results in increased road friction, which contributes to poor gas mileage.
Check the oxygen sensors and fuel injectors. This requires a bit more mechanical aptitude and special equipment. Thus, you may want to take your car to a qualified mechanic to have these components checked. If the sensors are not working as they should, the air-to-fuel ratio will be off, resulting in lower gas mileage. Also, if the injectors are malfunctioning, gas mileage may be negatively affected.
