I've been using synthetic oil since the early 1980's, and had great results with extended change intervals in my Volvos, up to 330K miles. But those were used cars, purchased sans warranty, so there was no expectation of a bail out if I screwed up. With a new car, my first goal is to meet warranty service requirements for the life of the warranty, but this also provides an opportunity for some baselining - what does the oil look like chemically when the engine calls for a change? Does the grade used (synthetic vs blend) make a difference? (I had always used full synth., but Ford uses blend unless you ask and pay.)
Blackstone Labs offers an oil assay service. Kits are free, $25 for the analysis when you send the oil in. I added $10 for a TBN measurement, as TBN is a measure of oil life remaining. (See the two links for details) I sent my first sample at 15,880 miles, and got it changed at 16,061 (today) for $35. Oil had been changed at 5,626, so this represents the full 10K mile interval. The service receipt from 5626 miles listed "XO*5W20*QSP OIL - ENGINE" which today's service writer identified as "blend" oil (part synthetic, part dino-juice). He installed blend as well.
Here's the start data.
PORTER-013114.pdf 17.38KB 56 downloads
I won't read you the comments, but I see two key results:
- there are a lot of wear products (Al, Cu, Fe, Mg, Si are high) consistent with a new engine.
- the TBN is very low; this oil is worn out.
I paid the premium for TBN, and I'm glad I did. We'll see what 25K brings!
If anyone else does an oil assay, post it and lets see if there's a pattern!
And if we have any petroleum experts, here's a soapbox... give us your insights (technical, not Honda).
PS IMHO, the easy way to do this (if you're not changing oil yourself) is with an oil extraction pump. Blackstone Labs sells a manual pump that looks quite nice for $30, but I got one of these. (Note: this method for oil changes has drawbacks unless you've got a hard-to-drain locations, like inboard motorboats.) Slip the inlet hose down the dip stick tube, and pump a few ounces into the bottle. As close to "no mess" as you get when motor oil is involved...