Guys/Gals,

We have been talking about changing oil on a per kilometer basis depending on the type of oil (mineral, semi-synthetic or fully synthetic).

Mineral/Semi-synthetic - every 5,000k change
Fully synthetic - every 10,000k change

If you don't travel that much (City Driving only and not that often long travel), what is the best time to change in terms of months?

Mineral/Semi-synthetic - not more than ?? months even less than 5000 kms
Fully synthetic - not more than ?? months even less than 10,000 kms

Need your expert advise.