How dirty is my oil?

[MelectroK]

K, I am using Mobil 1 syn. Now I have found diffrent post about how the oil lasts longer then organic. Some say it can easily go over 3000 between oil changes. My question how long is long enough? If the oil dont break down I assume it only needs to be changed when its dirty. How dark does it get before it needs to be changed?

Thanks

 

[rangerj]

You are right, oil does not break down, it gets "dirty". The "dirt" in your engine is a combination of the microscopic bits of metal from engine wear, and the contaminants that get into it from "piston blow-by", that is some fuel and air, including moisture and other crap in the air.

If you are in the big city where the air is full of pollutants, or in the country where the air is full of dust, it gets into your engine.

You can probably go 5K on synthetic oil, but I look at oil changes at 3K as cheap insurance. Look at SDPATTs SHO. It has almost 300K on the engine and he changes his oil and filter religously at 3K. That is a strong testiment to regular oil changes.

A clean air filter is also important.

You decide! rangerj

 

[HopefulSHO]

Even with synthetic oil, it will eventually wear out and not be able to neutralize the acids that engines produce. With Mobil 1, I'd probably go 6-7k before changing. Unless you're realllly beating the **** out of it.
I recently switched from Castrol GTX 10w-30 to Castrol Syntec 0w-30; I'll be changing mine at 6-7k intervals.

 

[SinisterSHO]

I've also heard that synthetic oil can be changed at 6-7k intervals, but the downside to that, is that most filters are still only good for three thousand miles. So, where you dont need to change your oil, the filter is going to lose its efficency before then.

 

[yamahaSHO]

With proper filtering, synthetic can last a VERY long time... With by-pass systems, there are people going up to and past 20k miles on oil. Synthetic doesn't break down like conventional oil, it gets dirty.

I know my dad runs synthetic in his 85 Toyota pickup... changes the filter every 4k and the oil every 8k.... Motor looks brand new inside.

 

[HopefulSHO]

Eventually the addative pack in any oil will deplete itself. Bypass systems, while keeping the oil hella clean, also generally increase the oil capacity too. Add in filter changes (more new oil into the engine) and you can keep your oil for a long time.

Most oil filters are good for much more than 3k miles. I have no qualms about using the stock sized Wix filter for 6-7k miles. I probably woulnd't run a regular Fram that long (I won't run them at all); and your filter actually filters better the longer it's in use. There are downsides to this though, as the filter can eventually plug, or start to flow poorly through the media.
Fact is in modern engines, they run clean enough so filters rarely clog on normal intervals.

 

[MelectroK]

But its not like the filter would detererate? I would just plug up right? So as long as i have good pressure that should be okay. I was only planning on going 4500 - 5000 miles with it anyway

 

[1stSHO]

I run Amsoil in my cars and Truck. I also run there tranny fluid and gear oil also. I love it and wouldnt use any thing else. I change the filter at every 3k and wait till 9k to dump the oil. I even use it in my push and rider mower

 

[SHOZ123]

I run Amsoil in my cars and Truck. I also run there tranny fluid and gear oil also. I love it and wouldnt use any thing else. I change the filter at every 3k and wait till 9k to dump the oil. I even use it in my push and rider mower

Sounds like me. I use Amsoil in everything I can. The '93 burns too much oil but everywhere else I use the synthetics.