Uim/Lim was done in July with an oil change then.
Today I decided to drop the oil & filter with 1700 miles driven, and go full synthetic with -48c rating for winter.
So as a trial, I went with made form natural gas, Pennzoil Platinum.

When you open the jug the first thing you notice is how pure clear it really is!
So after driving an hour and pulled the dipstick this is how it looked...

Ya that is pretty clear all right!
What really impresses me is how quiet the engine now runs at 600 rpm flat!
Before I popped the hood, it was hard to tell the Buick was even running!
Click on image below to see video...quiet isn't it!

Will have to see how it stand up in 3500 miles. This may be my new oil of choice, time will tell.

While at the shop we tested the Odyssey battery to see how it is doing..

Ya that is a strong pass at 1058CCA..good stuff!
Coolant reads -49C
The Michelin Destiny tires with 37k miles still have 90 percent left on them!
Power steering full & clean, Brake fluid clean & full.
Greased brake & hood cable. Oil to door hinges etc..
Also the undercoating is holding up and now really hardened.

Boots look good & no leaks..

The rear air shocks look a little rusted though! Maybe I need new ones!

Must be a marketing gimmick.

"100% full synthetic" is ALL man-made materials.

"Made from Natural Gas" is considered dino oil because during the natural gas extraction, dino oil comes up with the gas and voila, oil. So, where'* the 100% synthetic?

You make a very good point Mike.
From reviews I have read both Platinum & Ultra Platinum meet and exceed GF5 and Dexos.
Here is a video from Shell about the Benefits of Natural Gas Synthetic Oil.