A car tuneup is an outdated service consisting of replacing parts to bring the ignition and fuel systems up to spec for maximum engine performance and efficiency. A traditional tuneup hasn’t been available or necessary for years. Today’s remaining tuneup services include new spark plugs and cabin air filter replacement. Both are part of your vehicle’s maintenance schedule just as much as checking tire pressure or getting an oil change are — and today’s “tuneup” services are likely to be more like checkups for your car.