I have an oil analysis done periodically to see how the oil is faring typically about every 7,500 miles on an older 3 series BMW and a Merc GLC300. I use miles rather than length of time. So far no red flags, fingers crossed. Reluctant to extend more than 1,000 miles but gives me some peace of mind if I can't get to it immediately.
Extended oil change intervals impact on Wear
- Thread starter Roberts9156
- Start date
Most size particles in oil are very small <6um in size. Depending on engine, etc. Fuel, sludge, the list goes on for what is out to get our oil & engines. UOA can help. The best way I think to get extended intervals & collect more of those smaller particles would be a bypass filter. Doesn't make financial sense for many of us though so we simply use UOA, follow OLM, & or just change our oil before it's due. The longer an oil is run, the more it will get used up. Lots of variables & the folks saying "It all depends" are correct.
my response could be anecdotal but I think the longer drain intervals has more to do with fuel dilution and oil viscosity than wear metals in the oil. Lot's of extended UOA's on this site over time showing the PPM per 1,000 miles is pretty linear but the viscosity and fuel dilution are bigger impacts.
FWIW, I do EVIC OCI's on our 2014 T&C. When the dash says change it, I do. It is usually 8-9.5K and about annually. My Ram gets the same treatment, but with the short drives now I will probably go back to 5k intervals. That is ~1-1/2 to 2 years so long enough.
Some engines and oils fair better with extended drains than others. That said reasonable intervals with quality oil and high efficiency filters should keep contamination and wear at a minimum.
I tend to worry more about the oil and interval (time/mileage) and less about the filter efficiency. But that’s me.
I tend to worry more about the oil and interval (time/mileage) and less about the filter efficiency. But that’s me.
I think this is funny because it about the exact opposite of what everyone was saying when I joined this forum 20 some years ago. Everyone was trying to figure out how long they could go saying 3-5k OCI were a waste of money.
Times have changed chainged and I'm by no means saying you are wrong. Just pointing out how this forum discussions have changed
You may be referencing the amsoil and HPL fan clubs. Some follow science backed data vs the investment under their right foot and value the price of the oil vs their engine by doing long extended drain intervals. There is no right or wrong here some is good advice some is table salt. GDI and the bringing back of turbocharging vehicles has definitely become a game changer for vehicle maintenance and oil change intervals what worked on a 2007 Hyndai Sonata with a MPI 4 cylinder wont fly by today with smaller displacement turbocharged GDI demands. Today's biggest topic isn't necessarily oil change intervals it's my oil is too thin Australia uses 15w-40 why can't I?
Which for many manufacturers is the severe service schedule and, as most of us know, many/most people fall into this category.
Bingo, it's a happy medium. No need to over think the next oil change.
I have noticed this as well. When I first started lurking on my old Dell computer, German Castrol 0w-30 and Rotella were the darlings. Everyone was trying to see if they could do 10k or 15k mile OCIs. What wasn't there at the time were technologies such as GDI, and turbocharging wasn't as widespread. A thin oil at the time was an API 5w-30. 5w-20 was just starting to make the scene with Ford and Honda.
I seen a sign in O'Reilly's today that said 80% of new vehicles are spec'd with full synthetic oil. Things have gotten more demanding with GDI and turbos.
Patman
Staff member
A lot of people assume that 3000 mile oil changes will double the engine life compared with 6000 mile oil changes but it simply doesn’t work that way.
Most people on here still change their oil too often…
Most people on here still change their oil too often…
German Castrol and Motorcraft was always the sleeper budget oil
Yes! Every 3,000 miles and mostly Kirkland full synthetic. Changed the filter every 6-12 months or less depending on various factors. I have a MityVac and it's so easy. I think it only held about 3.8 quarts but cannot remember if it was with a filter. I really took good care of the old Honda Civic and still kind of miss it since I wanted to run it to 200,000 however it was starting to show its age. Bought a brand new 2025 Maverick hybrid that gets better mileage yet.
High efficiency oil filters catch way more particles that are <15u than a low efficiency filter. Some high efficiency oil filters that are 99% @ 20u are around 70-80% @ 5u efficiency. A low efficiency filter rated at 50% @ 20u might be around 15-20% @ 5u. Every oil filter has an efficiency vs debris size performance curve.
Engine wear is proportional to how clean the oil is and how long many times the sump is pumped through the engine (the OCI). The dirtier the sump and the longer it's pumped through the engine is going to increase wear from debris. This is why the longer the OCI is, better filtration will help mitigate wear compared to doing a long OCI with a low efficiency filter.
Last edited:
Wear increases as the oil becomes more dirty and the longer its ran. Think of it like liquid sandpaper between moving parts. If oil could be kept 100% perfectly clean then the only wear would be from moving parts rubbing together instead of the rubbing wear and then adding wear from debris caught between the moving parts on top of that.
Every controlled wear study shows that the dirtier the oil and the longer it's ran, then the more wear from particulate there is. If you ran an engine with no oil filtration for say 15K OCIs, it's going to wear faster than if you used a filter with 99% @ 20u efficiency on that 15K OCI. On the other hand, if you did 1000-1500 mile OCIs you wouldn't need much if any filtration on a broken in engine.
Last edited:
This tells me, that if I plan to reduce the typical 5000 mile OCI by 50%, in our newly acquired RDX (60k miles), for at least the first OCI, I don't need to source a high efficiency filter. Is this correct?
If your OCI is only 2500 miles then filter efficiency isn't as important. Some people always use higher efficiency filters since if buying the right ones don't cost much more or even less than some lower efficiency oil filters.
A lot of people confuse extended oil changes with lack of maintenance.
Engines or really any lubricated equipment won’t last any longer by guessing on the short side - frequency of oil changes vs logical data based OCIs.
Engines or really any lubricated equipment won’t last any longer by guessing on the short side - frequency of oil changes vs logical data based OCIs.
Similar threads
