If it takes me longer than 3 months to drive 3K miles, why should I change my oil?
Does the oil degrade over time? If so, does that mean oil left on the shelf for more than 3 months is no good?

 

... every 3 months?? Thats new to me. No, its just til you hit 3000 or if your taking it out of storage... You can get Synthetic and have it last alot longer If you have some really heavy mods I can see where your coming from. I change my vw oil after every 500-750 miles

 

The reason that I have heard was because of condensation collecting in the oil over time. They assume if you cannot get 3k miles in 3 months, then you probably aren't driving enough.

 

You change your oil because the detergents in it break down from combustion gases. So, once you put oil in your engine and start it- the detergents begin to break down whether you continue driving or not. I have seen soooo many low mileage older cars with the oil changed once a year and the motor looks like an ashtray inside. 3 months or 3000 miles- it's your motor.

 

There have been numerous studies which show that oil does not break down in 3 months. I know one came from Consumer Reports. The old adage of "every 3 months or every 3000 miles" is really just a saying from the oil companies to get you to buy more oil.

If you read your Acura Owner's Manual, you'll also see that there isn't anything in there about getting your oil changed every 3 months. It specifically, and only, mentions getting your oil changed at specific mileage intervals.



[Modified by Shmeek, 8:20 AM 1/16/2002]

 

the reason 3months is there is simply for people who don't write down their odometer when they change their oil, so they remember the month they did it. the average american drives 3000 miles in 3 months, so it makes sense that they would say that.

keep in mind that if you are storing your vehicle for a prolonged period of time you should either drain all of the oil out of the vehicle (along with all other fluids) and refill before taking out of storage, or change all fluids before you drive it out of storage. this is if you are going to be storing it for a long time, also, take off belts and replace hoses before driving as well (also disconnect batery). this is for like at least a year of storage. if all you are doing is going out of country for a month don't worry about it, just don't fill up your gas tank before you leave and have it as close to empty as possible and drive dirrectly to a gas station when you return (even for trips more than a week). I have gotten way off topic now


[Modified by samagon, 10:06 AM 1/16/2002]

 

Why leave the engine empty of oil?

 

moisture + oil + no activity = oil breakdown --> sludge

if youre storing your car for a while, you want to keep gas in the tank to prevent rusting.


dont have to change your oil every 3 months, its just the oil industry robbing you of easy money. But if you do change it more frequently, your engine will be cleaner. Frequent short trips over time where the car does NOT fully warm up, will cause the engine to bronze up in color which means sludge is slowly building up.

 

My GSR owner's manual states every 7,500 miles for an oil change, with no mention of time. Since I average about that in a year (75k mile 2000 GSR), I change oil close to annually.

That said, I change the oil in my rarely driven "weekend car" every 6 months or so. Unlike more modern cars, it has an open crankcase breather which tends to collect moisture in the oil over time. Last time I took it in, the shop asked why I was changing the oil after 25 miles, since they had recorded previous mileage in the computer. Eh, that was an 8 month time span, so it got new oil, 25 miles or not.