We here have the oil tested at least twice per year on the road rigs. Pick
your own test labs. The only way to determine what is or is not working in
the lube requirements is to test the oil.
There is a by-pass filter on my truck Diesel block, just as John describes.
It pulls about 1/2 gallon of oil per every minute or so at 1500 RPM and
pipes it through a bypass filter( after the main filter) at a rate of about
5-10 psig. The main Fleetguard filter- filters at about 2 to 5 microns. The
bypass is about the same. The real trick here is the low pressure of the
bypass filter. The through-put of the bypass system is set deliberately low
to allow the oil to spend more type working its way through the media. Thus
the fluid can better reach the media lower micron size. FWIW, we are now in
the process of designing a trickle rate (consumption) oil bypass that
triggers off a timer at about 7500 miles. The goal here is to pipe the 7500
mile oil to the Diesel fuel, injector pump, and burn this as fuel. We have
seen these in action on some stationary blocks and one typically adds new
15w/50 API-C4 oil as needed. The only blocks here that use syn-oils are the
stationary engines. The basis for this is the ease of starting in cold
weather. The over-the road blocks here run “easily” up to 200K miles and
more on conventional “C” rated non-syn-oils. Generally, and after monitoring
and keeping good records (for the past thirty years) of maintenance and wear
points, the engine in and of itself is the most reliable component on the
chassis or frame. After 200K road miles there are so many marginal
sub-assembly components attached to the entire vehicle, that are or have or
need to be replaced it is not a practical thing to be concerned about an
additional 50 to 200K miles of use from the block. For example replacing
the shocks every 20K miles shows the shock towers are rusted beyond
practical use. Brake lines, u-joints ( replaced at least twice) rotors,
calipers, alternators, water pumps multitude of fried smog monitor sending
units pitted windscreens door gaskets etc. on and on. Unless one has painted
and coated all such ferrous base things the wear is very obvious. There has
been significant up-grades in longevity since the 1960’s on all cars and
trucks generally owned by the everyday consumer. but there is still a
countdown clock to recycle time that must happen.
Probably a vehicle that is driven in the southwest would be an minor
exception here. Added to this and here in the upper Midwest it is salt,
sand and calcium chloride that constantly works on the metals and further
decreases the half-life of the main vehicle.
To practical to be fun
Dave 89 XJ6
John said:> No “full flow” type oil filter can effectively remove the
ultra fine combustion “blow-by” products which are so
abrasive to engine components. Some diesel engine
applications use an extremely fine “partial flow” filter
(along with a full flow) for this purpose and they still do
not recommend extended intervals when using a synthetic
versus a conventional.