do-it-yourself Mechanic:  The Gas Thief

Copyright 2004, Donald Harris
Cars Trucks and Tractors


The gas Thief can be disguised in several ways and can strike in more than one way simultaneously.  Some of the common "thieves" are under-inflated tires, dirty air cleaners, and forgetting tune up intervals.

Check your owner's manual or if you have misplaced or lost the owner's manual, look at the manufacturer's stickers on the door, under the hood or in the trunk of the car.  Usually the manufacturer's recommended tire pressures can be found in more than one place.  Following the manufacturer's recommendations will help optimize your fuel economy and tire life.  Under-inflated tires increase the rolling resistance and reduces gas mileage.


The air filter is one of the most overlooked items in auto maintenance.  We remember to change the oil but if the auto shop forgets to remind us to check/change the air filter, it goes unnoticed.  Dirty air cleaners will cause the engine to run "rich" and increase pollution as well as decreasing fuel efficiency.

The tune-up is often forgotten until your vehicle starts performing poorly, starts missing, or becomes hard to start.   When these noticeable symptoms occur, your engine is well past the manufacturer's recommended tune-up time.  Check your owner's manual! It will give recommended service intervals for all your vehicles components.  This is only an educated recommendation based on "average" usage.  Consult your mechanic.  He knows your vehicle and you.  He will recommend service based on your vehicle's use and driving habits.  Heed his advice.

The fuel system can rob you too.  One of the easiest ways to maintain your fuel system is to add a fuel system cleaner to your gas tank when you have your oil changed.  There are several good brands of fuel additives available.  Follow the additive manufacturer's instructions as to the amount to add for your fuel tank's capacity.  This will help keep deposits from building up in your carburetor/fuel injection system and keep your engine running happy.


Donald Harris is a former mechanic and used car dealer.  He continues to tinker under that ol' shade tree.  Drop by his website at

for car repair tips and links to parts, manuals and classic cars, trucks and tractors.  Also visit

for advice on living a modern life without the modern headaches!  You can contact Don at

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