[TR] How often should I change oil in triumph that rarely does muchmileage?

[Hoyt Duff]

One method of increasing the  period of time between oil changes is to
replace the filter only at 6 month or 6,000 mile intervals and top up
with the same brand/viscosity of synthetic oil with adequate ZDP and
Phosphorus to protect our flat tappet cams. While the base oil itself
does not wear out and  an hours' drive can purge any volatile
contaminants, there are several components of modern oil that do
dissipate over time, hence the one quart replacement with a new
filter.

>From what I have read, all synthetics except AMSOIL are blended
synthetics. All modern synthetics do not demonstrate any of the
horrible things you have been told.

Honestly, for our rarely-driven British cars, I suspect we could do
pretty much whatever we want, absent outright neglect, and they will
outlast us.

-- 
Hoyt