Tom Kizzie wrote:Is it possible (maybe) that you drove a lot of shorter trips in your pennzoil time?
"when an engine is started the oil pressure needs to build up in order for it to fully protect the engine. Lots of cold starts means lots of times the oil isn't protecting the engine adding to the wear.
Also when the engine is cold the mixture is run rich to aid combustion. This extra fuel can result in bore wash due to it running down the bores washing the oil away. This fuel then enters the sump diluting the oil meaning the oil can't protect as it should. In extreme cases of lots of short runs and cold starts the oil level may rise due to the oil dilution with fuel. You can usually tell if this is a problem as the oil will smell of fuel. Prolonged bore wash will eventually lead to bore wear.
Excessive carbon build up can also occur due to the rich mixture on continuous cold engine use. The carbon will also contaminate the oil.
If you are doing a lot of short journeys with a cold engine you should change your oil more often due to all the above reasons"
No, my commutes were the longest when I had the Kizashi early on running Pennzoil Platinum.
I also noticed the burn-off with Mobil 1 even during the time I was driving in the same manner as the Pennzoil Platinum. Basically, only the oil brand changed and that's when I noticed burn-off between oil changes. This is the reason it caught my attention. While my driving routines have since changed, I noticed the burn-off with Mobil 1 was consistent over around the 40K miles I used it which included living on opposite ends of the United States and having different commute distances. While it's not a scientific measure, I'm pretty confident the correlation is with the oil.
I don't consider it a bad oil by any means but it gives me a reason to try something else to see if I get that burn-off.
I also recall writing about Mobil 1 burn-off observations here years ago. It hasn't changed.
I also don't neglect my oil. It gets changed about every 7500 miles and I use top-tier filters like Mobil 1, K&N, or Purolator ONE.
I'm not too concerned and more interested in trying something else, especially for this value.