":::Jerry::::" wrote in message
...
I think you're being a bit strong here. When Mobil 1 first appeared we
were
able to stop changing the oil three times a rally. In fact it would
probably have lasted several rallies, such was it's lack of degradation
under harsh conditions.

I think the operative word is 'rallies', here we are talking bog standard
road going cars...

Which until the recent WRC cars were at least related to bog standard cars.
Often they were just the bog standard cars with the weakest bits upgraded a
bit.



Also changing oil and filter every 6k would cost more than using a
synthetic every 18k.

No it would not, unless you buy oil from the retail rip off stores or
petrol
forecourts...

Not sure how nuch you pay for oil then but synthetic is less than three
times to the cost of standard even before we consider the filter.