If the spark plug deposit indicates black coating of soot, it indicates that the engine has been generally operating on ...
too lean mixture
most economical mixture
too rich mixture
4 Unusual Road Signs to Know Before Your Driver's Exam
These weird road signs can appear on your driving exam!
5 Things They Don't Teach You in Driver's Ed Class
Ease those driving test nerves with these driving test tips to help you pass!
Keep your life a-buzz with quizzes!
Pick one or all types of notifications and fine-tune them to your liking.
Get Trivia Quizzes via…
Top 5 Players
Can you tell the difference between fact and fiction? Click Yes or No to answer simple yet interesting questions.