Car Maintenance and Gas Mileage - Myths and Facts

As gas prices continue to rise, the auto industry is out in full force touting the benefits of car maintenance. Many repair shops even have custom "fuel saver" services. While maintaining one’s car is indeed important, does it really save gas? Before we answer this, let’s step back and look at auto maintenance for today’s cars.

The first question we need to ask is – what does my car need (according to the manufacturer) for it to be considered "maintained." Today’s cars no longer have distributor caps, rotors, points, and a variety of other ignition components – so these don’t need maintenance. Many vehicles now come with extended service parts such as 100,000-mile platinum spark plugs and life-time fuel filters. Oil change intervals have been extended to 5,000 miles or more. The 3,000-mile oil change is ancient history. Coolant flushes and transmission services aren’t needed until 100,000 miles if at all. Yet, even if we performed all the above services, will they increase fuel efficiency? Probably not. Unless your vehicle is misfiring (i.e., not running on all cylinders), you’re gas mileage is likely fine.

So what part of car maintenance adversely effects gas mileage for the average driver of a late model vehicle? Three things: tire pressure, air filters, and excess carbon.

Tire Pressure: Setting your tire pressure is free, and is the best maintenance service you can perform to maintain maximum fuel efficiency. It’s that simple.

Air Filters: Air filters can indeed get plugged after a considerable amount of driving and can then restrict air flow, which will not allow your fuel to burn efficiently. This can also cause excess carbon build-up, which can reduce miles per gallon. The good news: air filters are cheap ($15 to $30), are easy to install, and usually only need replacement every 30,000 miles.

Excess Carbon: There is another auto maintenance service that "can" help gas mileage. It’s called a fuel system cleaning service. Some repair centers call it fuel injector auto maintenance, or a fuel injection service. Simply, chemicals are added to your fuel system through a variety of orifices to clean out excess carbon deposits on your valves, pistons and intake manifold. This naturally forming carbon (in excess) is not good for gas mileage. Excess carbon absorbs gasoline, which would otherwise be used to power your vehicle. However, before you run out and spend the $150 + to have this service performed, there is one important consideration – the service will only work for vehicles that need it. In other words, yes the stuff works, but you’re vehicle may not have any excess carbon build-up. You wouldn’t wash clean clothes – right?

When you see those "fuel saver" services for $100 to $300, they’ll likely include an air filter, tire pressure check, and a fuel system cleaning service. If you’re wondering whether or not your vehicle needs it, ask yourself the following:

1) Do I use quality gasoline consistently?
2) Have I replaced my air filter at least every 30,000 miles?
3) Have I checked my tire pressure recently?

If you can answer these questions affirmatively, you’re probably ok. Buying cheap, no-name gas once-in-awhile is ok. Replacing the air filter and setting your tire pressure is common sense. Also, if you drive like grandma, get out on the highway and press the vertical pedal at your right foot "all the way to the floor" until your vehicle accelerates to speeds at which you’re not all too entirely comfortable. Then repeat a few more times. This will help clean out excess carbon – FREE – less the cost of fuel. Be careful. Watch out for cops.

In summary, follow your manufacturer guidelines for your car’s maintenance – not ones designed by those who stand to benefit most. Use name-brand fuel, set your tire pressure now and again, pop in an air filter, according to your car’s recommended interval, and don’t be afraid to drop the hammer now and again.