What does a tune-up consist of? Air filter, spark plugs and wires are just some of the traditional aspects of a tune up that can lower emissions and help improve gas mileage. The performance of most cars can be disrupted by a lack of fuel, air or ignition issues. If your vehicle is struggling to start, let Mechanics Plus help get your vehicle running properly. To help your car function as intended, a proper tune-up will help your vehicle last as it was designed to.