Hi,
Shannow - This is a synopisis of the methods I and many of my Customers use/used to mdel outcomes from variances to "accepted" practice in the Trucking Industry. Accepted practices are very hard to break down due to inherent and natural conservatism, variable technical skill levels, mixed Fleets and applications etc.
The Manufacturers recommendations are stage one in the process
In Trucking these are typically conservative and based on Fleet maintenance and servicing processes outside a selling or servicing Dealership
Typically these cover daily checks (by the Driver), regularised Inspections by Service pesonnel to a set routine and OCIs as they have determined (along with the engine's manufacturer) for various applications. The results can be influenced by the skill levels of staff so training must always be considered
Stage two is confirming these in practice
With engine lubricants the base level lubricant and OCI is monitored. The same applies to drive line lubricants and their OCI. used oil analysis are a great tool at this stage.
The cost factors here (labour. oil and filters) are known. The downtime and operational management factors always intrude and typically lead to some "elasticity" in the actual intervals.
This can be dangerous as in OTR work the engine's OCI can be every two/three weeks or so. This takes a vehicle out of service for about one day at a time
Stage three - outside the square
At this stage "widening the envelope" is always a factor of the skills and enthusiasm of the personnel involved and the willingness to perservere
a) Starting with engine lubricants, once the base level (standard lubricant/filter) is confirmed (say 15kkms OCIs) used oil analysis will quickly tell at which stage the OCI is actually required.
In my experience this was at around 25kkm. Viscosity increase (soot) was typically a major condemnation factor and wear metal limits were rarely reached. The way individual lubricants handle elevated soot levels becomes evident quite quickly
b) A move to a better quality lubricant - say a semi-synthetic was the next stage. Typically this was good for around 35kkms - about a 50% increase in vehicle uptime at very little cost.
Again IME viscosity increase was a major factor
Already the vehicle downtime factor had been substantially reduced
Stage four - model the alternatives
The next stage is to economically model the alternatives - typically, as follows 1) move to better/different filters, 2) move to a better lubricant (stock levels/availability), 3) move to a better lubricant and filter
4) availability of service points/skilled personnel
Break even points are established on the way with the possibility of increased uptime as a bonus!
Of course I always continued with regularised drive-over-pit Inspections by skilled people and of course the documented daily Safety Inspections by every Driver. Drivers check coolant/lubricant levels, tyres wear/damage/perceived inflation, lights, belts etc. Typically this is a 15 minute job to a set and established/published routine that is "signed off" as a commitment
Stage five - confirming the moves
Typically this is done based on these factors: a) increased vehicle uptime as a bonus, b) monitoring component condition, c) lubricant condition (UOA at break even point then calculated intervals until OC required), d) filter condition and contents at OCI
The break even point in my move to a synthetic lubricant, LL filters and a By-Pass centrifuge occurred at double the distance of Stage three b) above (35kms x 2 = 70kkms)
My enduring actual average OCI across all vehicles was established at about 90kkms or six times the Manufacturer's recommended OCIs with a base level lubricant and filters
Vehicle downtime due to OCIs was reduced by a factor of six!
This was a saving in skilled peresonnel and operational distortions. It was much easier to plan for one day out of service in say five months instead of one day every three weeks
This is a typical outline. Most trucking Companies are conservative by nature, have "mixed"Fleets (Makes & types) and are reluctant to change too much!
Warranty concerns some as extended engine Warranties can extend up to 1m kms. High power engines here in Oz are around $40 000 to replace.
I can't quickly recall any lubricant caused engine failures except perhaps when an incorrect lubricant has been used cuasing sludging and the Manufacturer;s OCIs have not been followed as well
One gearbox of mine failed (on Hume thru Albury) after the oil was drained in Sydney at 1m kms and not refilled - the service point paid all costs (about $19K) of course!!
One of my engines was still going well at over 2m kms without overhaul the last time I spoke to its present Owner
Optimum
I always standardised on a compromise. Not the longest OCI but the safest at a point (90kkms) that was always reliable as determined by countless used oil analysis. Many times we went out to 110+kkms between OCIs and one engine went to 130kkms with all UOA factors in a reasonable state
I hope this is of interest
