We will be putting only 6k miles per year on our 2005 Focus ST ZX4 .
Is there any harm to just changing the oil and filter every 5k miles, vs the
recommended 6-month schedule. At our mileage level, we would be changing oil
about every 10-11 months. The car is operated in a relatively dust free
region, and consists mostly of 3 to 20 mile trips, but almost no
stop-and-go commuter traffic.
I use 5w30 wt. Mobil One synthetic on my 1997 Crown Vic , which I realize is
not an extended range oil, but I have had good luck with it on that car on
the 5k interval, vs by the 6 month schedule.
Also, I will check the owners manual for viscosity, as I don't yet know what
the recommended weights of synthetics are for the Focus.
Any of you use synthetics for the 2.3 liter dohc engine? If so, what weight