Expert advice on car maintenance

Oxygen sensors are not among the maintenance items that need to be replaced regularly, so they typically are replaced only when they fail.

A car’s thermostat typically requires replacement only if it fails, but more complex systems in modern cars may require assistance from a mechanic.

Asking your mechanic for a general tuneup isn’t really a viable request anymore — nor is it likely to be the fix for a running problem.

While having too little oil in your engine can understandably cause problems, having too much oil can be just as bad.

High-mileage oil can include additives to reduce wear, corrosion and leaks, but stick with the manufacturer's recommendation and only switch if such signs appear.

Conventional wisdom typically sets no time or mileage interval to replace drive-axle boots, but that's the simplified answer.

If your car is making a squealing or squeaking sound when you turn the steering wheel, there could be any of several culprits at play.

Using regular gas in an engine that requires premium could void your warranty if it causes severe engine knock or pinging.

While not an immediate threat, sap can etch through the paint's clear coat after some time, leading to discoloring and staining.

A general recommendation is to replace the positive crankcase ventilation, or PCV, valve every 30,000 to 50,000 miles.