1. Change the oil every four thousand miles, religiously. Use regular oil, not synthetic; buy the highest quality regular oil you can find; 10W30 is fine for most applications in most cars. (check your owners manual) Whenever you change the oil, always change the oil filter, too. Funny things can happen inside of oil filters, and it's best not to push them too far.

2. Keep all dirt OUT OF THE ENGINES! This means change air filters and fuel filters regularly. Make sure the air intake system has no leaks which could allow unfiltered air to enter.

3. Never ever let your cars overheat. Caution your drivers to stop immediately and get it fixed if their car begins to overheat. Overheating means premature death to all kinds of hoses, seals, and gaskets in your cars.

4. Do not let your drivers hot-rod the cars. Drive them normally, exerting normal stresses on the various parts.

5. Set up a regular maintenance schedule for all your cars. Schedule the maintenance around your 4,000-mile oil changes. That is, while each car is in for its 4,000-mile oil change, do whatever else is scheduled at that time.

Make sure that one of the top technicians inspects each car during the oil change. You want him to take a look at everything and report any abnormalities. A low-skilled oil-change guy is a very bad idea. A wheel could be falling off, and he might not notice it. You want some sharp-eyed technician who can quickly spot anything which seems to be going wrong.

6. In general, replace parts, don't try to repair them. Replacement parts are made in factories, with the efficiencies of mass production. Parts repair is almost always a big waste of time in a fleet maintenance operation.

7. In general, use high-quality remanufactured parts where available, except for engines, where you should go with used engines, where possible. It's very hard to remanufacture an engine properly. The original manufacturer did a better job than the remanufacturer can usually do. Transmissions are a different story, however: we use Ford rebuilt transmissions which come in a box from the factory.

8. Avoid cheap tires and batteries. They are more trouble than they are worth. (Avoid cheap parts in general, for the same reason.) Buy all-season tires and maintenance-free batteries. Keep the terminals clean and dry on your maintenance-free battery. Since no battery acid should be able to reach your terminals, there is no need for any kind of grease or corrosion inhibitor. If you see corrosion, replace the battery: there is a leak.

9. The only real advantage to tire rotation is that it makes all of your tires wear out at the same time. Replace your tires one-at-a-time, as needed, if you like. If you find unusual tire wear, fix the underlying problem, which is usually worn front-end parts resulting in bad alignment.

10. Do not let anything squeak for very long. Squeaking means that improper friction is happening somewhere in your car. Find it and fix it.

11. Do not let anything grind for very long. A low-frequency grinding noise means that actual destruction is going on in your car! Find it and fix it.

12. Encourage your drivers to develop their sense of smell for automotive smells. Gasoline is one smell; exhaust fumes another; burning oil is another; transmission fluid is one smell, motor oil is another; coolant is a sickly sweet smell; brake fluid is another smell; battery acid is another; brakes overheating is one smell; rubber burning is another. These are the main ones. Encourage your drivers to learn them, and pay attention if they suddenly start to smell any of them.

13. Warn your drivers not to drive when a red warning light comes on. Tell them that the red ones are serious and must not be ignored. Better to stop the car and catch a cab than to destroy an engine for lack of oil, for instance.

14. The yellow warning lights are not as serious. They do demand attention, but the drivers don't usually need to interrupt a trip to get them fixed immediately.

15. Encourage your drivers to get to know their cars and love them. Tell them to be aware when anything seems to change for the worse. Tell them to pay attention and be aware of their car just as they are aware of their own bodies.