Blackstone Oil analysis at 52k/45k/37k

[strat61caster]

Hey all, some more blackstone analysis numbers.

Oil used
Eneos 0W-20 (37k sample/42k sample)
Eneos 5W-30 (52k sample)

Each oil change done at the service manual 7.5k, I'm not easy on my car, it sees cold driving and track days and autocrosses. Each oil change has 1-2 track days on it and multiple autocrosses (I'd say 4-6 days, ~5 runs each).

And I've never filled it to the "full" mark

I ran 5W-30 under the impression that I'd be tracking/autocrossing a lot on hot days, the reality is I'm lazy and cheap and a competition addict so I've just been autocrossing and I've switched to Subaru brand 0W-20 at 60k (not going to send in a 60k sample based on how good these are), no worries as the iron levels have come down and this thing looks like it'll be solid (according to the oil at least, definitely not a guarantee it won't go pop someday).

Sorry I was too lazy to dig up whatever UOA compilation thread, I'll link it there if someone wants to be pedantic.

[Scrappydoo]

So wouldn't the conclusion be that 5w/30 is best?

[Stang70Fastback]

Here's mine doing 10,000 mile intervals on 0W-20 oil with autocross, ice racing, and year-round DD duties in Chicago.

[strat61caster]

Originally Posted by Scrappydoo

So wouldn't the conclusion be that 5w/30 is best?

Not necessarily, it only continued the trend shown in the first two, there wasn't a dramatic increase in improvement to my eyes and I do a lot more cold driving than hot and as a commute car I'll take the fuel savings too. I'll do a uoa of the 0w-20 when it runs through probably this winter and update. If the particulates jump up I'll agree with you that the engine is in steady state wear and the 0w-20 wears faster than the 5w-30, but right now I'm inclined to believe I've caught the end of the engine settling in for the long haul.

It also had slightly less track abuse than the two 0w-20 samples as my co driver was a novice (double duty that day, car ran like a champ except for the coilpacks)

I think one of the conclusions of this data (among many others posted before me) is that the 7,500 mile interval is fine, even with some hard running, all this b.s. about changing oil every track day or 3k miles or the 0w-20 is too thin is just throwing money out the window. Sure there are special circumstances, but as pointed out by Stang above me an even longer interval can be performed with confidence.