Dear Tom and Ray:

My son has a 1991 Honda Accord. He drives about 17 miles each way to work every day--city driving--and the car has about 17,000 miles on it. The oil is changed every three months or 3,000 miles, whichever comes first. The car doesn't burn any oil, but the dipstick shows a dark, almost black color whenever I check it. One mechanic said it could be a hot motor. Another said not to worry about it. What do you think?
Harry

RAY: As long as your crankcase ventilation system is working properly, it's nothing to worry about, Harry. The fact that the oil is black means it's doing its job.

TOM: One of the oils' jobs is to pick up deposits and contaminants inside the engine. And the reason the oil is dark is because it's holding all those contaminants in suspension.

RAY: Chances are it retains at least a little bit of its gold color for a week or so, but after a week or two of hard city driving, it's not unusual for oil to look like that reconstituted mocha-beet-celery juice my brother buys at the health food store.

TOM: So don't worry about it, Harry. Keep changing the oil frequently, and this car will last as long as your son can stand driving it.