Tell him when problems first became apparent and under what driving conditions. Consider writing down a list of symptoms or keeping a log of possible problems. Your service advisor will inform you of the problem when the technician has had time to properly diagnose it. All of this information will be appreciated by the technician and will save you a lot of money over the life of your vehicle. Changing your oil regularly is the single most important service you can do for your car, and it's one of the easiest.
Dirty oil creates leaks, scored bearings and over consumption.
You can never change it too much but we recommend every 3,000 miles. Oil is the lifeblood of the engine. It not only lubricates the engine, it also cools, cleans and protects it. But mineral oil by itself can't do all of these jobs without some help. Nearly half a pint of various additives are added to the typical quart of mineral oil to improve the oil's ability to resist heat, friction, oxidation and contamination.