Hey guys,

Been wondering what I can really get away with on fluid changes for my 97 4.6.

Its got 265k km on it, I have had it since 2000 and I have in the past religiously changed fluids at regular recommended intervals,

Engine oil every 5k km
Coolant 50k km or 2yrs
Transmission 50k km or 2yrs
Differential 25k km or once a year.


Well, I now have a company vehicle and a second car with the old lady, the truck is my second vehicle when the old ladies out or we go camping. Its averaging 7k km a year over the last 4 years

I have heard engine oil will breakdown over time and should be changed a minimum of once a year.

Haynes recommends coolant and transmission fluids changed out once every two years.... but its really hard justifying changing out transmission fluid with only 15k on it... Am I wasting my time to change it out every 2 years just because its "old" or can I get 4 out of it? Same for Coolant and Differential.

I'm curious if anyone has any "facts" about fluids breaking down or not over time by just sitting there, or if its all a matter of opinion.