Want to help the environment and save on gas?
You should tune your car!

A misfiring spark plug can reduce fuel efficiency as much as 30%. Follow the service schedules listed in your owner's manual or ask a Auto Specialist for advice. One of the most important factors for long engine life is timely oil changes with the right oil for your driving habits. Replace filters and fluids as recommended.

Underinflated tires wastes fuel to compensate your engine has to work harder to push the vehicle. Wheels that are out-of-line (as evidenced by uneven tread wear or vehicle pulling) make the engine work harder too. Properly maintained tires will last longer, and this means that fewer scrap tires will have to be disposed of in a year.

Have it serviced only by a technician certified competent to handle/recycle refrigerants. Air conditioners contain CFCs - gases that have been implicated in the depletion of the ozone layer. According to the Environmental Protection Agency, almost one third of the CFCs released into the atmosphere come from mobile air conditioners; some simply leaks out, but the majority escapes during service and repair - so its important that you choose a qualified and legal technician.

Mileage decreases sharply above 100 km/h. This consumes greater amounts of fuel and increases the 'liters per hundred kilometers' ratio.

Avoid sudden accelerations and jerky stop-and-go's. Use cruise-control on the open highways to keep your speed as steady as possible.

Consolidate your daily errands to eliminate unnecessary driving. Try to travel when traffic is light to avoid stop-and-go situations. Join a car pool if possible.

Remember, how your car runs, how you drive it, and where it's fluids are located, old parts and tires are disposed, all have serious consequences for the environment.

And how fit your car is, is very much up to you, the owner. Perhaps years ago, a shade-tree mechanic whose only credentials were a tool box and busted knuckles was enough. But not today! Today's high tech vehicles need more.... and today's quality-conscious consumer demands more.

Every ten days, motorists who drive with under-inflated tires and poorly maintained engines waste 70 million gallons of gasoline.
-- Car Care Council

Each year twenty times the amount of oil spilled by the tanker Exxon Valdez in Alaska is improperly dumped into North America's environment by do-it-yourselfers.
-- Automotive Information Council