today's dumb questions>
1. this oil report, one data point in time: does it tell me the damage and wear of this engine over the last 59,000 miles? I used mobil 1 synthetic about every 5000 miles every time.
2. should I change oil earlier JUST because of 2.2% fuel dilution. especially Mr. Newton. letting the oil go longer, or using cheaper oil, how would that affect fuel dilution. If the fuel gets in so many ml per day, changing oil at 10,000 miles would give me a 4.4% dilution????? linear development?
3. at what point is fuel dilution definitely harmful?
4. would using a "great" oil, HPL or Amsoil allow me to change oil at 7500 miles? this car STILL does short trips. 4 miles and 8 miles. Massachusetts is cold in winter, car likely never warms up.
5. was this 7.5 centistokes OK at 100C?
1) you can't use single micro-data UOAs to determine trends; further, you need large groups of UOAs to understand standard deviation and normal bounds. That's something that should be familiar to you if you've had any data training; statistical data processing isn't unique to UOAs. What single UOAs can tell you is if the wear at that time of the sample was in "normal" bounds relative to macro data (general population). It can also ID significant contamination issues (fuel; silica; coolant; soot).
2) Generally most folks agree that while fuel dilution isn't desirable, it's generally harmless below 5%; lower always better of course. We've seen many, many UOAs with fuel dilution higher than yours and still have acceptable wear.
3) fuel is "harmful" when it greatly escalates the wear rates; your data isn't near that by any means
4) any "great" oil could go 7.5k miles. But so could the oil you're using now. And so could several lessor cost lubes.
5) the vis is OK; about the center of the 20 grade range;
https://bobistheoilguy.com/viscosity-charts/
My goal is not to save money on oil, but save the engine. car runs like new. all work done.
Save the engine? From what? Are you implying that destruction is imminent because you're using Mobil1 every 5k miles?
Sir, you're being overly sensitive here. The lowest cost ST lube would suffice quite well for 5k miles, and very probably give you about the same wear rates.
My goal is NOT to change oil too often and waste resources. am willing to try Amsoil and HPL and do oil tests.
Then consider stretching out your OCIs. Try 7.5k miles the next change and take a sample. If all is good, then 10k miles. Frankly, you are wasting resources in your current OCI plan. Even conventional lubes could easily do 5k miles. Heck, many are capable of doing 10k miles quite well. What you need to understand is that syn lubes do nothing to dissuade the effects of fuel dilution. So using a "great" expensive syn lube isn't going to make you able to extend your resource conservation IF fuel content is your main concern.
You're going to have to make a decision here, because some of your goals are counter-indicative. You cannot say you want to conserve resources, and yet change a syn oil every 5k miles.
- if the fuel content scares you, and you're 100% committed to doing frequent OCIs, then quit using such expensive lube, as any API appropriate house brand would do just as well.
- if you are willing to monitor the fuel level, and are willing to experiment with longer OCIs backed up with UOAs, then by all means do so!
When you get a chance, please read this regarding UOA data analysis:
Reviewing UOA Data Used oil analyses (UOAs) are tools. And like most tools, they can either be properly used or misused, depending upon the application, the user, the surrounding conditions, etc.= There are already many good articles and publications in existence that tell us how to interpret...
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