Engine oil change periods, for gentle driving and low annual mileage?

[daver clasper]

Hi. I know that service schedules, say to change oil after a certain length time (6 months for my Vitesse I recall?) regardless of mileage.

I'm interested to know why this would be so necessary, for my driving situation?.

I do around a 1000 miles per year, of mainly longer distances and not thraping it at all.

I intend to keep the car indefinitely though the total likely mileage I will do, will still be relatively low, so any wear will not be maybe too crucial, I assume?

What harm to the engine could this maybe do (and how and why?), if the oil was changed, say every two years and approx 2000 miles.

Genuinely interested (as well as not wanting, to throw money away unnecessarily).

Thanks, Dave 

Edited April 15, 2023 by daver clasper

[glang]

I know oil technology has improved a lot since the manual was written so maybe back in the day the oil started to deteriorate (oxidised, moisture, chemical breakdown) after even just a few drives. Once contaminated the process continues even if not driven more so the oil needs to be changed...

[Rosbif]

For my 13/60 it says every year or 3000 miles whichever comes first, in my case it is the time scale as I do around 1500 miles per year.

I use a classic mineral oil.

[RobPearce]

As glang said,  oil does suffer chemical degradation from being exposed to air and other conditions in the engine.  It's quite slow on modern oil,  so you don't need to change it more than annually. 

[Clive]

On such a low annual mileage, I would be happy to change the oil annually, but the filter every 2 years. Making sure the oil was drained from the filter (just not running the car for a few days should do that)

[daver clasper]

Thanks Guys.