Engine oil Mobil or Shell

I have a 2001 Forester L and I enjoy using Castrol Edge 5-30 during winter and Rotella T6 5-40 during the summer in Arizona.

I’m on rotella t6 on my ‘05 Impreza at 217k miles. Just had all the seals replaced. It has been on rotella since 132k miles. Runs really good.

Porsche wanted you to use 0W-40 originally but now they recommend 5W-50 which is what Porsche sell for the 996 as their Classic oil for the 996. I’ve used Mobil 1 5W-50 for 3 years now, good pressure and next to nothing on the magnetic drain plug since so seems to be working. In my last change I’ve also added Ceratec on recommendation of another member of this sub and since have noticed the engine is a little quieter and get slightly better mpg so would recommend giving that a go if you are so inclined.

I use Mobil1 0w40 for the last 3 years (changed twice a year) with flawless UOA reports. I upgraded this summer to M1 5w50 as I do get low pressure warnings at times during high heat and heavy traffic situations summertime. Winter going back to 0w40

In my VN, always Mobil 1 0w-30 AFE.

I vaguely remember a video or a study done on mobile? Syntec or something, a somewhat scientific study pulling samples every 1k miles and sending out to a lab. Bottom line was that the oil actually got better over miles and they abandoned the project at 15k miles.

I live in a dusty climate I change my oil at least annually and I use Mobil one in my Volvo, Kirkland synthetic in the kids cars, and rotella in my air cooled vw.

I use Rotella T6 5W40 on my stock motor STI.

My wife drove her 2008 Passat 2 miles per day for six years. As you can imagine, during these very short drives in winter, the oil became diluted - this was born from sever UOAs. So, I changed the oil every 1,500 miles and the oil and filter every 3,000 miles. Over-kill perhaps but based upon my personal expectations, worth the time and money. We used Mobil 1 0W40....which sheared to a 0W30 fairly quickly and stabilized.

my valvetrain was always noisier when I used to run Mo1 0w40.