Results of used oil analysis - updated 5/23/11

[striktlyaccord]

So I sent my used oil out to Blackstone Laboratories with a check for $32.50 about 2 weeks ago and got the results back last week.  I have a K24 auto that had 56,072 miles (at time of testing).  The oil tested had 6,616 miles on it and was Mobil 1 5w20 full sythetic.  All of the metal wear elements they tested for were within normal ranges, and the other tests that measured things like insolubles and remaining additives were fine.  Here's the write-up that the lab provided:

"Universal averages show typical wear metals for this type engine after about 6,500 miles run on the oil.  Your oil was in use 6,616 miles, and we found all wear at around average levels and in the correct balance to show normal mechanical parts inside the engine.  Air and oil filtration (see silicon and insolubles) appear normal.  The was 5W/20 engine oil with no fuel, moisture or anti-freeze in it.  The TBN was 2.8, showing lots of active additive left.  1.0 is too low.  The oil could have stayed in use longer.  Try going ~8,500 miles for the next sample and check back to see the results."

Guess this is all good to know.  My mechanic actually rode me a bit that I went too long on my oil change and should change the oil (even synthetic) at about 5,000 mile intervals.  Needless to say, when he saw the results of this test, he was a little shocked.  But hell, the Honda manual says to change the oil every 10,000 miles or 12 months, so long intervals on Honda engines seem to make sense.

[v6sicksspeed]

wow - i didn't expect that.  what Mobils recommended change frequency with m1 full synthetic?

[InFuMoUs]

Now you have nothing to worry about on how long you can go on M1 5w20 right Dave?

[clapton924]

These results do not surprise me one bit.  I see oil analysis reports like yours all the time.  Run your oil to 8,500 as the lab suggests and re-test.

Honda's 10,000 recommended interval is for non-synthetic oil (the cheap stuff) under "normal driving conditions"  Honda's 5,000 recommended interval is for non-synthetic oil under "severe conditions".

Honda classifies "severe" as:

1. Driving less than 5 miles per trip or, in freezing temps driving less than 10 miles per trip.
2. Driving in extremely hot conditions [over 90F].
3. Extensive idling or long periods of stop-and-go driving.

Most full synthetics (mobil-1, penzoil platinum, valvoline synpower, etc) have a protective, and useful life of ~10,000 miles in our K-series engines.  This is just a guideline...to find out for sure test your oil.

[striktlyaccord]

Yeh I agree Greg.  The Honda intervals are all based on conventional grade oil, so full synthetic can be run for quite a long-ass time.  Honestly, it'll probably outlast your oil filter.

[msedacca]

I still change mine every ~3,000 miles, otherwise Skip would have a conniption haha

just messin bud

[striktlyaccord]

I still change mine every ~3,000 miles, otherwise Skip would have a conniption haha

just messin bud

Waste of $, and bad for the environment.  

[timot_one]

Moved.  Please read:

General Discussion
A place to talk about anything automotive or forum related that doesn't fit in any other category. Specific performance or technical threads are not allowed and will be moved or deleted.

[v6sicksspeed]

ive been thinking of switching to synthetic lately and this thread may have made the decision for me

[striktlyaccord]

Moved.  Please read:

General Discussion
A place to talk about anything automotive or forum related that doesn't fit in any other category. Specific performance or technical threads are not allowed and will be moved or deleted.

I didn't really think this was a performance or technical topic.  Oh well.

[mitchigan]

This is what a few engineers in the industry told me when I asked them, "Engine oil can last up to 50K+ miles, but then no one would ever buy engine oil nor check their engine oil levels, so manufacturers pounded those magical 3K 5K 10K numbers into the consumers head."

[striktlyaccord]

Just recently sent out used oil again to Blackstone Labs for analysis.  This time, it was run for about 8,400 miles.  Results should be in soon.

[striktlyaccord]

I got the results of my 2nd used oil analysis sent to me on Friday by Blackstone Labs, and things are looking good once again.  This time around, my oil change interval was a little bit longer per their recommendation at 8,253 miles (64,325 total miles on the K24), and I used the same oil & filter combo as last time (Mobil 1 5w20 full sunthetic oil and a Mobil 1 oil filter) with similar mostly highway driving patterns.  Similar to last time, most of the wear metals were all within normal ranges, and the TBN test that they do to measure insolubles and the remaining cleaning agents and additives actually had better results than last time. Here's the lab's comments:

"Now that's what we call consistency--at least so far.  The oil was run about 1,500 miles longer than last time and yet wear metals were exactly the same.  That's a great sign that the engine is doing well.  Insolubles were unchanged at 0.3%, so the oil filter was getting the job done.  Silicon actually dropped a little, so we don't see any problems with air filtration.  No fuel or moisture was present in the sample, along with no abrasive contaminants.  The TBN was 3.4, better than last time.  Try an even 10,000 miles next time.  The engine shouldn't mind a bit."

So, this is good news.  I'm just surprised that the oil filter can last this long, but the oil itself doesn't surprise me.  Looks like I may be following Honda's recommended oil change intervals for normal driving going forward, which are at 10,000 miles.

[status]

awesome.  although i will probably continue to do it at 5000 just because i only drive 10k a year if that.

[Mike]

Dave can you give me a little information on how to get this done as well as the cost. I would like to do a couple of these to see if I can change my oil a little less that price of oil is going no where but, up so I'd like to save some cash and do my part for the enviroment at the same time.