How often do you change oil in a car?

Answer 1

Every 3 months or 3000 miles, which ever comes first.

I must respectfully disagree with the first answer. The 3,000 mile oil change is promoted by quick lube shops and by some dealers. They make money on this myth which was true years ago. In reality it is not necessary to change the oil that often on most modern vehicles made within the last 10 years. Open the owner's manual and follow the recommendation of the manufacture which you will find is not every 3,000 miles. Some manufactures on some models do still recommend every 3,000 miles but not many. Commonly you will find it is 5,000 to 10,000 miles. Filters, oil, and engines today are built much better than they were just 10 years ago. Plus the modern engine management systems with fuel injection provide the optimum 14.7 to 1 fuel/air ratio that the old carburetors rarely attained. This allows for a cleaner and more complete burn of the fuel. This eliminates excess fuel getting into the oil. We also do not drive in dusty conditions as we did years ago. If you drive in normal conditions then it is a waste of money and oil to change your oil every 3,000 miles of 3 months. Follow the manufactures recommendations as listed in your owner's manual and you cannot go wrong.

I must agree in part with the second answer.

However with the correct Oil and Filter you can go 25,000 to 30,000 miles or 1 year which ever comes first.

NOT QUITE. I learned about determining the oil change interval for vehicles in the Army, and info from Consumer Reports also agrees with what I learned:

Modern motor oils are formulated with detergents to help suspend contaminants, so color of the oil won't tell you if it's good... in fact, today's oils are fine for around 12,000 miles, or up to 20,000 for synthetic.

Now the filters on the other hand, are only good for about 4,000 to 5,000 miles before they are too dirty. All filters have a bypass valve, so that instead of starving your engine for oil [killing it], the oil simply goes around... unfiltered!

Add to these 2 factors that oil has risen in cost much more than other things [$5 a quart * 5+ quarts = $25 to $30]. This has led me to using the following method for best engine life:

I only change the oil every 12,000 miles, BUT I change the filter every 4,000. About a quart typically will drain when the filter is changed, so it gets topped off. I use 3 different filters, so I can tell from the filter color whether it's time for a full change.

This keeps the oil perfectly clean & the sight addition during filter changes compensates for thermal breakdown. Why would I bother though? well, I tend to rack up 85,000 miles in about a year, and that would be 21 changes, about $525!! with my system though, I only spend about $250! So this saves almost 50% no matter whether you drive a little or a lot [you still buy half as much, just the dollar am amount changes.]

However far you are going, be sure to check the level regularly.