It's hard to give a specific time or mileage figure because the life of the filter depends on how much crud it ingests. A filter that lasts 20,000 or even 30,000 miles on a vehicle that's driven mostly on expressways may last only a month or two in a rural setting where the vehicle is driven frequently on gravel roads. Changing it annually or every 15,000 miles for preventative maintenance may be a good recommendation for the city driver, but not its country cousin.

The type specified by the vehicle manufacturer in your owner's manual. For most passenger car and light truck gasoline engines today, it's any oil that meets the American Petroleum Institutes "SH" rating. As for the viscosity of oil to use, most new engines today require a multiviscosity 5W-30 oil for all-round driving. The lighter 5W-30 oils contain friction reducing additives that help improve fuel economy, and also allow the oil to quickly reach critical upper valvetrain components when a cold engine is first started. Most engine wear occurs immediately after a cold start, so it's important to have oil that is thin enough to circulate easily -- especially at cold temperatures.

Not unless you are willing to risk electrical damage or a fire! A fuse is a protection device that is designed to blow if the amp load in a circuit exceeds the "safe" limit for that circuit. Fuses are built with a specific amp rating which is marked on the fuse. The wiring and design load of the circuit dictates the size of fuse that's required to protect the circuit. Circuits that draw a lot of power need fuses with high amp ratings (20 or 30 amps) while those that use minimal power require smaller fuses (5 to 15 amps).

The first and most likely indication of a low battery would be a hard starting problem caused by slow cranking. If the battery seems weak or fails to crank your engine normally, it may be low. To find out, you need to check the battery's "state of charge." A battery is nothing more than a chemical storage device for holding electrons until they're needed to crank the engine or run the lights or other electrical accessories on your vehicle. Checking the battery's state of charge will tell you how much juice the battery has available for such purposes.

You need a "brake job" when your brake linings are worn down to the minimum acceptable thickness specified by the vehicle manufacturer or the applicable state agency in areas that set their own requirements. The only way to determine if new linings are required, therefore, is to inspect the brakes. You may also need a brake job if you're having brake problems such as grabbing, pulling, low or soft pedal, pedal vibration, noise, etc., or if some component in your brake system has failed. But if the problem is isolated to only one component, there's no need to replace other parts that are still in perfectly good working order.

The parking brake serves as a mechanical emergency backup brake system. Should your hydraulic brakes fail, the parking brake can be used to stop the vehicle. Many people who have vehicles with automatic transmissions rarely use their parking brake. They simply put the transmission into park to lock the drive wheels when they park their vehicle. Even so, it's important to use your parking brake periodically.

A steady miss indicates one of three things: a cylinder that isn't firing because of an ignition problem, a cylinder that isn't firing because it isn't receiving fuel (multipoint fuel injected engines only), or a cylinder that has lost compression. The first step in diagnosing this kind of problem is to identify the dead cylinder. A professional mechanic can do this quickly by hooking the engine up to an ignition oscilloscope and displaying an ignition raster pattern. The dead cylinder will show a firing voltage that is significantly higher or lower than its companions depending on the nature of the problem. He might also do a "power balance" test and/or a compression test to find the dead cylinder.

It will tell you if your engine has good compression. An engine is essentially a self-powered air pump, so it needs good compression to run efficiently, cleanly and to start easily. As a rule, most engines should have 140 to 160 lbs. of cranking compression with no more than 10% difference between any of the cylinders. Low compression in one cylinder usually indicates a bad exhaust valve. Low compression in two adjacent cylinders typically means you have a bad head gasket. Low compression in all cylinders would tell you the rings and cylinders are worn and the engine needs to be overhauled.

You try to figure out why it failed the test, get the problem fixed and then try to pass the test again. This may or may not be an ordeal depending on what's wrong with your engine, how easily the problem is to diagnose and repair, and whether or not you flunk a retest. The worst case scenario is spending a lot of money on repairs only to find that they didn't solve your emissions problem. You bounce back and forth between the repair facility and test station, wasting time and money all the while cursing the incompetent mechanics who tried to fix your car and the bureaucrats who created the clean air emissions testing program.

Yes, because your engine is burning oil. That, in turn, means your engine has worn valve guides, piston rings An engine that burns a lot of oil (more than a quart in 500 miles) is an engine that needs to be overhauled. Normal oil consumption should be a quart or less in 1500 miles. Most newer engines consume less than half a quart of oil between oil changes (every 3000 miles). So if your engine is burning oil, it's essentially worn out and needs to be repaired.