I would have to say every 3,000 miles or every 3 months. It couldn't hurt. It is best to get a full work up and catch any problems before they become expensive fixes. Vehicals will last longer when good care and service is applied.
Inspect at least once a year, base service on what you see.
I have found that the filter should be changed around 90K in normal use and 60K in severe conditions. Toyota Tech.
Some cars like a BMW and a Mercedes do not require service ever so often. But models like Toyota and Honda do require annual service to be on the safe side.
once a week is recommended
You should get your floor machines serviced once every other year. They require regular upkeep in order to last a very long time.
Annually. If it`s fueled with oil absolutely annually.
Toyota's need to be serviced often.. otherwise they tend to turn their engine oil into sludge. this may be your problem.
Your fuel tanks are built to last the lifetime of your vehicle. They should only need to be serviced if they are damaged in an accident, or if some contaminant has been added to the tank.
once a year, or 15,000km whichever comes first.
HVAC should be serviced about twice a year. I prefer service just before summer so I'm not left in the heat and just before winter so I'm not left in the cold.
Toyota recommends every 90K.
That will depend on how the vehicle is used and what the manufacture recommends. It could be as soon as every 20,000 miles or as long as 100,000+