I noticed while ordering the Amsoil for the Amphicar Extraordinaire
that they (Amsoil) reccomend 25k miles or 1 year.
What is the reccomended or accepted interval when using Amsoil
There are actually a variety of factors to consider in AMSOIL motor oil
change intervals. These involve the type of vehicle, its use and its oil
filtration system. The optimal situation would be a normal (i.e. "land")
vehicle in a decent state of tune running AMSOIL with one of their special
additional oil filtration systems installed. Some vehicles can get away
with motor oil change intervals of up to 35,000 miles. More details on the
variety of scenarios can be found in PDF format at http://www.amsoil.com/lit/intvlgui.pdf .
As far as the Amphicar is concerned, given the seasonal nature of its use in
most climates, and its operation in a necessarily harsher, or at least
wetter environment, a complete fluids swap (motor oil, trannies and at least
an examination and topping off of the coolant fluid) and at the end of each
"boating season" might be advisable. Not having a garage myself, I go
through a whole "Winterization" drill each year as described at http://www.geocities.com/SoHo/8389/winterization.html . Once a year for
everything has worked well for me, but Amphis living in warmer climes with
heated garages might get away with longer intervals with no ill effect.