Vehicle tune-up helps to keep your vehicle's performance, also if your vehicle is hybrid , you should not be missed the tune-up(at least every 40000 km need perfect tune-up) otherwise it may impact hybrid battery life time. how do you know your vehicle need a tune-up Some of below points can be identified, May dashboard lights on - check engine Bad fuel consumption Engine misfiring Unusual vibrations Slow pickup Differ engine sound note : When you replace spark plugs, should be genuine