[314]

2015 mazda 3i AT, 68k miles.
14k miles between oil changes, mostly highway driving.
dont remember which brand 0w20 i used for this 14k miles. (i've used Penzoil, Mobile 1, Castrol, Valvoline, and Quaker. whichever is cheapest at the time. :surprise

"This oil was in use for about 14,000 miles and that's a respectable interval for this engine.
The average run we see from one of these 2.0L engine is just 7,000 miles.

With that in mind, it's nice to see all metals testing within the average range. To be sure, iron is a bit elevated, but that's expected on longer than average oil runs because of the way that metal accumulates in the oil with use. Fuel dilution was present at 1.0% of the sample, but that's a harmless find and no other contamination was found. Check back to start trends and monitor.
So far, so good."


think i'm going to try 20k miles with Penzoil 0w20 (what i have now), then 20k miles with Mobile 1 15k mile 0w20.
and get oil reports on each

 

[M3Nitro]

2015 mazda 3i AT, 68k miles.
14k miles between oil changes, mostly highway driving.
(i've used Penzoil, Mobile 1, Castrol, Valvoline, and Quaker. whichever is cheapest at the time. :surprise


think i'm going to try 20k miles with Penzoil 0w20 (what i have now), then 20k miles with Mobile 1 15k mile 0w20.
and get oil reports on each

I use Blackstone all the time and have for years(couple or more decades) on many fluids.

I would not challenge the oil, so to say and keep to oil and filter changes at minimum 10k miles. Oil is cheap easy to do.
I can tell you that it is far better to know a problem beginning then to deal with a really big problem later that may have been corrected.

 

[Datsun1600]

2015 mazda 3i AT, 68k miles.
14k miles between oil changes, mostly highway driving.
dont remember which brand 0w20 i used for this 14k miles. (i've used Penzoil, Mobile 1, Castrol, Valvoline, and Quaker. whichever is cheapest at the time. :surprise

think i'm going to try 20k miles with Penzoil 0w20 (what i have now), then 20k miles with Mobile 1 15k mile 0w20.
and get oil reports on each

Really great results, and kudos to you for attempting to push the boundaries to see how far you can go and still maintain good engine protection. I'm sure that "highway miles" has a lot to do with it.

One question though, if you do a 20k mile interval with Penzoil and then with Mobile 1, you aren't necessarily comparing apples to apples due to the increased age of the engine. I think in order to make a valid comparison you'd have to try Penzion, Mobile 1, Penzoil, Mobile 1, etc. to see if there is a trend in contaminant accumulation due to engine age.

Thanks for sharing your results. I recently switched all our cars to full synthetic and was initially nervous about a 10k mile oil change interval. But no longer after reading all these great reports from folks going to longer service intervals!

 

[M3Nitro]

This is a usual report if anyone did their first oil service long before the recommendation of the auto maker. Personally I wouldn't want this stuff circulating around my NEW engine for 10 thousand miles.:laugh2:

Varnish can build up on internal engine parts that will not necessarily show up on an oil report. This is generally from people that like to "TEST" how long they can go between oil changes. That varnish can cause minor things like noisy HLCs (Hydraulic Lash Adjusters) to a build up around oil passages.

IDK? IMHO seems it is always the next owner of a vehicle that ends up with someones poorly thought out LAB Experiment and correcting it bad results.