Oil change intervals can bring about as many opinions as hair color in women or brands of oil among techs. There are light and heavy duty among many other items to consider. Many of the newer one have the interval figured by the body computer taking into consideration number of cold starts, highway miles driven and time spent idling and several other factors depending on the model.When I had 3 cars to take care of I just changed one ever month, made it simple but then over the years my kids got cars they married and their spouses had cars and my stable increased to 5 of my own. Now the situation became a little different. I would say to check the owner’s manual first and to follow the schedule and weight of oil they suggest. Stay away from the 0-30 and 15- 50 and other extreme weights stick with either 5-20,( only during severe cold) 5-30 or 10-30 There is a certain amount of leeway in these schedules so they are not hard to follow. Many now allow 6 months or 6000 miles between changes sounds like a lot to me but oil and engines have improved. Use any oil that has a starburst on the container and stick with the same brand, I would also use a name brand and not a store label IE Checker or OReillys. GM, Ford, Chrysler and the rice burners all sell their own oil but it is usually overpriced.With the dollars we pay for our vehicles I think using synthetic is a no brainer sure it is a little more expensive but it also protects and lubricates more efficiently. If you live in a colder climate then I would definitely use synthetic it is more efficient at cold starts. Oil change intervals should also be shortened in the winter if you live in a cold climate. Today’s computer controlled fuel systems do an excellent job of cold start fuel control but there are containments entering the oil during cold starts and short trips during cold weather. Manufactures discovered several years back that a thinner oil lubricates the upper part of the engine more efficiently so they tend to recommend thinner oils at lower temperatures I would lean towards the conservative side of their recommendations by conservative I mean to use the higher temps on the cold side and lower on the warm side. Good luck and remember it is more important to change your oil regularly then to worry about schedules. If you change your own oil please dispose of it properly