I had this thought last night before i fell asleep. do we really need to change our oil? since our car burns oil and we have to replenish it every no and then. i figure in the amount of time that passes between oil changes i put almost that much oil in the car anyways. I know it's good to change it anyways, but i'm just bored as hell right now.

 

Yes.
Frequent oil changes are the number one thing you can do to prevent premature engine destruction.

Adding new oil to used oil won't remove the carbon/gasoline contaminants that cause oil to breakdown and fail as a lubricant; it will merely dilute them.

 

Quickest way to kill a rotary: Don't change the oil regularly.

As someone on a Subaru forum said: "Change the oil, not the engine."

Old oil kills rotaries. They're much less tolerant of abuse than a typical low output piston engine. Oil is cheap enough, and rebuilds suck. I try to change mine every 2000 miles or 3 months, whichever comes first.

-=Russ=-

 

The fact that our cars burn the oil in the combustion/compression chamber should make you just a little bit more weary about having a bunch of dirty oil, don't you think? I certainly don't want to inject dirt onto rotor housings, especially after seeing how delicate they are to wear lol.

--Gary

 

I know it's bad to not change the oil. like i said it was one of those random thoughts passing through my mind before i went to sleep. Not to mention i was bored. I wouldn't dream about not changing it; but like i said, random thought and product of boredom.

 

Similar question: The Mazda book that came with my car has the oil change intervial at 7500 miles. That seemed a little high to me so should I be changing it every 3k or so?

 

You will get a different answer from everyone. I changed my oil every 2k miles for 3 years on my old vert. I have read posts on this site saying that if you change it more than once every 5k miles then you are wasting money.

It is well worth it to me to have fresh oil in my car. I have never let any one of my FC's (4 in the past 5.5 years) go more than 3k miles between changes.

 

Can you probably go longer than 2k? Certainly. My oil still is dark amber when I change it.

However, the amount of money wasted in frequent oil changes is significantly less than the cost (and annoyance) of a rebuild. Plus I premix, so I get more oil dilution than running the MOP setup.

-=Russ=-

 

7500 ? - kilometers maybe.
My owners manual says 3750 miles.

I change a 3000. It's easy to remember. I write it on the oil filter.