Since our car was new we went by the manufacturers recommended service schedule of twice a year but now the warranty has expired and we only average around 7000km per year i was thinking of reducing the servicing to once a year. What's the opinion's, is it necessary to change oil and filter twice a year ?
Car manufacturers' warranties are generally based on 12,000 miles (19,200 km) per year so changing your oil and filter once a year should be plenty for the mileage you do.
This is not an expert opinion, but doing frequent small trips puts more strain on a vehicle than the same mileage on longer trips. It is partly due to engine warming, Damaging products will build up and a long trip at times would help clear them. But it may not be advisable to cut down on servicing, especially oil-changes. The battery might run down more quickly too.
Not enough information for me to make a recommendation. Ford makes a lot of engines. Could be diesel, could be gas, could be turbocharged, hmm? I do find it interesting that they told you twice a year. Ford PI could be different but most manufacturers maintenance schedules will tell you a mileage and months, with the caveat "whichever comes first." They will also offer reduced mileage or months for heavier duty cycles. Usage like towing, excessive idling, heavy foot, off road, mountains come to mind. Industrial and marine will be on hours run. For all the stuff I do work on, not Fords, I can't recall any saying 6 months with the exceptions of a first or break in service. I have only seen 12mo, 24mo, 36mo ETC.
Strictly speaking engine oil and filter, I would be OK with recommending the first of 5000km or once a year. You surely could be fine with 7000km or once a year but like I said previously, there are many factors that would cause a reduced interval. There are more factors than what I mentioned and trying to quantify them as whole isn't going to happen from me. Modern USA autos can run the intervals Senjenbing mentioned. They use larger oil volumes and the engines control module to compute when to turn on the service reminder message. My Toyota Tundra 5.7l could go as far as 10000 miles but with my lead foot I've been seeing 6000 miles between changes.
