The Truth About Additive Depletion | Noria Corporation

Some additives in our oils additive package are designed to be used up as our oci progresses, others are degraded with time & conditions during the drive cycle & oil change interval (oci) & thus may show up in a uoa but Not be in a condition to be doing their job, so how do we know when its time to change our engine oil, tranny, or power steering fluid, differential fluid, brake or clutch fluid, coolant, wheel bearing, or chassis grease????

Well with the right kind of analysis & interpretation there-of, we can skate right up to the edge & get the most use out of our fluids, But it'll cost extra $$$$ for those uoa's. So to avoid extra costs how does the average owner know when its likely time to change????

If for example we have a vehicle with a Oil Life Monitor (OLM) system, it can help us get the most from our engine lube. For most of us without the OLM, or not wanting the extra expense of used fluid analysis, to be safe, we should opt for the manufacturers "severe service" interval called out in our owner manual, as most of us probably have our drive cycles fall into the category of short trips/severe service.

Anyway, keep those fluids changed at the specified interval & with products that say in writing, that they meet, or exceed, those specified by the vehicle manufacturer & enjoy the ride!!!!

 

A brief, easy to read & understand description of what we may currently find in our motor oil recipe, what it does, or means, in the case of a VOA = Virgin Oil Analysis, or UOA = Used Oil Analysis. Engine Oil Analysis - Bob is the Oil Guy - Bob is the Oil Guy
The type of UOA used to determine what's in the sample & what form the compounds are in, can help determine how a particular oils recipe is holding up in our engine, under the use we put it through during our OCI = Oil Change Interval.
As noted in the first article, the UOA can detect the Bulk of a particular Element, but not necessarily the condition, or compound state its currently in, so we don't know if its still active or effective, how effective, or if its depleted, or has formed an oxidized/degraded, harmful compound. So, we have to look at other indicators, like wear metals, (iron, chrome, aluminum, copper, lead), to get an idea how metal part wear looks for our engine, compared to the universal averages of like engines UOA wear metals over the same OCI miles, to get an idea how our engine is doing on the lube recipe & filters we're using. If wear metals look average or lower than the universal averages, our lube & filter choices are likely doing ok & the oil ad-pack is likely holding up, under the use we're putting them through.

Other indicators, like insoluble/particles, or a UOA particle distribution count, indicate (how well the oil, air & fuel filters are doing) & can be indicators on if unusual element wear indicators are due to a physical problem from abrasive particles being passed by a faulty, ill fitting, or sub spec filter, or if high element wear indicators are from chemical wear (rust, corrosion) from an internal coolant leak, or condensation, if the lubricant Base & Tan numbers or potassium, or sodium levels are out of the norm for our engine & chosen lube recipe for the miles used, compared to the averages the analysis lab has on record for our engine & VOA of the particular oil recipe we're using.
Base number depletion, or unusually high Tan figures could be from too long an OCI, using sub spec oil, or from an acting out clogged up stuck closed PCV valve, or faulty PCV system fittings, or from excessive piston ring blow-by from ring land deposits causing stuck rings, or from short, low mile drive cycles, especially in cold weather where the engine never gets up to full operating temp, or ring or cylinder bore wear, or maybe from a messed up air/fuel ratio caused by faulty sensors giving the computer corrupt feedback, which then causes it to corrupt fuel trim, all a vicious circle.
High Potassium or Sodium indicators can mean an internal coolant leak, if the numbers are above those for the oil recipe VOA figures.
SO, if we're having problems, a UOA, properly performed & interpreted, can give us some useful insight into how our lube & filter choices are doing in protecting our engines & how well our engines internal gaskets, seals, parts, PCV & EGR systems plumbing & parts are holding up.
Of course, for those of us that don't use UOA, how long we can likely use a fluid has been tested & mathematically modeled by Ford Engineers for us & the worst case scenario has been allowed for in their description of "Severe Service" & in the design algorithm for Fords IOLM = Intelligent Oil Life Monitor, but if our drive cycle is always severe & we like to skate close to the edge, to get the most ROI = Return On Investment of our fluids & filters, UOA trending over time can help in problem solving diagnosis, or prevent our going over the edge on our ROI quest!!!! A bunch more thoughts for pondering.