Oil and change frequency?

[Alati]

I got my 2009 Mazda6 with 160k miles on it about a week ago. Absolutely love it. Of course it has its quirks and faults and whatnot, (if someone can tell me why it likes to try to jump out of my driveway when I reverse the first time after I start it each day that’d be cool) but I really just want it to take the best possible care of it and, well, I’m not super car savvy, but I’m trying.

Since is has so many miles on it I should change the oil more often than the usual 3k miles right? Is there a specific oil I can use to reduce wear on the motor? And gas, will using a higher grade increase longevity or make any sort of difference?

Sorry if these are super noob questions, I just wanna do right by my new partner in crime.

 

[Grubbworm]

I change the oil in my 2021 Mazda 3 about every 5000 miles (give or take) with 0w-20 Castrol Edge Full Synthetic and a K&N oil filter (with the nut on the bottom). I also use a quart of Motor Flush before every oil change. Mine calls for 0w-20 oil, but I would use the weight oil yours calls for.

 

[N7turbo]

Since is has so many miles on it I should change the oil more often than the usual 3k miles right?

And gas, will using a higher grade increase longevity or make any sort of difference?

You'll be happy to hear that the answer to both of your questions is: no.

Stick with 5,000 miles on synthetic oil meeting API SP spec (virtually all should).

And you don't need to spend money on an engine flush product but you may want to give Valvoline Restore & Protect a try for one or two cycles to see what it can clean out of the engine.

 

[banjos-n-beer]

I had a 2005 Mazda6 for about ten years. Fantastic car.

Just change the oil every 5,000 miles. Use a high quality oil that matches the recommended weight.

And buy regular 87 octane gas. All you’ll do is waste money buying the more expensive grades.

 

[Mazdiod2]

How often you change the oil is about how much pollution (combustion byproducts, wear from metal parts in the engine, dirt passing through the air intake) accumulates in the oil, plus the oil gets worn out gradually from the heat and friction, etc., causing the oil to become 'thicker' but less effective at reducing friction.

When the engine is older and the parts worn some it can make the oil polluted sooner, but unless your car smokes a lot or has other problems it shouldn't be a problem.

Another way the oil gets more polluted is excessive idling and/or lots of stop and go driving without enough longer trip/highway driving to counteract the accumulation of unburned fuel and combustion products like water, which can turn the oil more acidic.

The one year time limit on oil is there to take care of these kinds of issues, and the only times I have changed the oil at less than 3K.