I would say at least once every 3-4 months.
Whenever it gets dirty.
Every 15,000 miles.
Every other oil change, drain water valve once a month.
How often should you change the fuel filter?
Every 4000 miles. Change it when oil is changed, along with oil filters
Diesel, once a year or 15,000 miles. Gas, no service required. (it is part of the pump in the tank)
Change the oil filter every time you change the oil.
You should change a furnace filter every 2-4 months.
My garage have changed it at 5213 mileage, which seems very low to me? Any ideas?
every 3000 miles
when it is dirty
Diesel smoke is often caused by fouled injectors, in which case the smoking can be cured by pouring a dose of good injector cleaner into the fuel tank on the next fill-up, and change the fuel filter, too. And change the engine oil and filter!