Changing your oil based on time

[Rocky_]

How important is it? If for example one has 500 miles till his next recommended oil change, but is 3 or 4 months past the recommended date, does it matter a whole lot?

I merely ask because my father does not believe that oil has to be changed by the date and only by the miles. And even then he says there's no problem going 2k over the recommended.


Personally I think that is stupid.. An oil change should be done every 3 or so months and every 3k miles or 5k.

My main question is, is time(months) really a factor in when you should get your oil change even if you haven't gotten gone a whole lot of miles?

I hope that makes sense. Thank you!

[NoUse4aName]

Get an oil analysis done.

Here's the comments on a report of mine done with a 7,800 mile interval using Mobil 1 by blackstone labs.

You've added about 2900 miles to the oil change interval and your engine didn't even notice. Wear read so close to the last sample that both oils could have come from the same drain. You have a very nicely wearing Toyota engine and we don't think you've reached the limit on how long you can run the oil. We suggest going to 8500-9000 miles for the next fill. The TBN was 2.5, still active additive remaining. A reading of 1.0 or lower is too low. The used oil was in perfect condition for this type and grade, and we found no harmful contamination in it.

Oil does breakdown over time, but it's not a concern until you're talking 6months+ and haven't met the mileage threshold yet. I like to get a change in pre and post winter regardless of mileage.

[GSBoek]

Mileage is the determining factor, unless you only drive 3000 a year in which case you change it every 6 months.

[marc]

depends on the oil.

synthetics are generally good for 15,000 miles / minimum once a year.

Since I drive both of my Porsches maybe 5,000 miles a year each I change the oil before I put them in storage every winter so they're not sitting there with crap in the engine.