Can I Change My Motor Oil The Next Time I Change The Oil Filter

by admin on November 4, 2010

I am often asked how many miles you can use a particular motor oil.  Folks usually ask if they can change their oil filter at some XXXX miles and leave the oil in longer till the next filter change.

These are tough questions with dire engine consequences if answered wrong. 

Here’s why.  Running oil and filters too long will result in excessive internal engine corrosion, excessive wear damage from dirt and debris bypassing the dirty filter, and higher potential for sludging as the oil oxidizes.

All those bad things result in your engine going bad faster.  Maybe it becomes difficult to start, maybe it loses compression and has a sluggish and weak throttle response or maybe it overheats and or seizes…

The consequences are enough to make you think twice about extending your oil changes willy nilly.

So to answer the question:  Oil does not last forever in an engine.  Engine oil is in a constant battle with heat, fuel, contaminated intake air, and exhaust products that are constantly trying to break it down.  The life of the oil is heavily dependant on the TBN value an oil has.  The higher the TBN typically the longer the oil can be used.

TBN is an oils ability to neutralize acids introduced from the combustion process.  Acid attack is bad for the metal in your engine!  The higher the TBN the more acid it can absorb so the longer the running life of the oil.  If your engine environment goes acid for a long period then kiss it goodbye.

If you want to go longer between oil changes then have a good look at the TBN number of the oil…

The oil filter is another story.  Crappy filters only catch the bigger particles and have a low holding capacity meaning they plug up fast.  There is a bypass valve in oil filters that prevent you from starving you engine to death when the filter media become plugged.

There are cellulose filters and there are synthetic media filters and they all have different abilities of catching particles of different sizes.  We want our filters to have the ability to catch the smallest particles and to have the highest dirt holding capacity to allow them to last longer.

I wouldn’t run a cheap filter longer than 3,000 miles.  Wait let me rethink that… I would never use a cheap filter so scratch that last comment.  Good filters are typically more expensive and there are some out there that provide safe protection out to 25,000 miles.

In my mind a little extra money for a quality filter pays for itself ten fold in the long run.

Look at the dirt holding capacity and look at the particle size efficiency to see if you have a good one.

If you are searching for the best motor oil and oil filter then check out my free report here.

Leave a Comment

Previous post:

Next post: