"jw 1111" > wrote in message
...
> Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say
> around 5000 miles, mainly
> on fairly short distances around town. what would be the 'time' limit to
> reasonably extend oil changes for economy reasons using a semi synthetic
> oil ?
>
> I suspect a lot of people will immediately say don't economize in this
> way.
> However some forty years ago I had a conversation with a professor of an
> engineering college and he said engine oil does not degrade 'time wise' as
> fast as most people think ( and importantly as the oil companies would
> wish us to
> believe). So by how much time could one reasonably delay an oil change
> with
> modern oils?
>

I revcently had this argument with a Mercedes main dealer.
I have one car that does very little mileage.
Thier position is that its not "10,000 miles or one year whichever comes
first",
its every 10,000 miles.
So the car should not be serviced until the indicator on the dashboard says
so.
They say its because of the more modern engine oils.
Personally I would rather pay for an oil change every year regardeless of
anything else that needed done.