Mobil 1 or Pennzoil?
 

Hello guys, I know Mercedes recommends Mobil 1 for our cars. Should I use synthetic oil for petrol engines or I heard of people using diesel oil to (15W40). I know that Mercedes switched to hard cams after 1987 so ZDDP is not as critical anymore. Under 1500 to 1000 is fine. So synthetic for sure but witch brand. Mobil 1 I heard is not even (PAO) = non synthetic?) I have no idea. I have narrowed it down to two great brands.:confused: I live in Wisconsin, so I know to run lighter oil in winter (5W30) and thicker in summer(15W40). Companies these days.... When it a comes down to it, nobody can trust them. They say one thing and actual product says another. Somebody please help, I do not want spun bearings!! Thumbs up for this site!!!

I use Rottela diesel 5w40

I have M103's and M104's.

I use it in my gas and diesel engines even my 22re

Is it synthetic? I think our older cars do not require synthetic. But then again oil technology has come a great way since then.

Oil unless it is dirty with abrasives will always lubricate properly. Diesel engines create abrasives suspended in the oil (soot) faster than their gasoline counterparts...Detergents are added to diesel purpose oils to separate soot and enhance lubricity. Studies here by many conclude 5,000 max oil-change on diesels....somewhat higher for gas using say Mobil-one. Dyno oils require more oil change frequency...depending on......alot!

now I use Mobil One syntheic atf,and Rotella or Mobil One diesel when I can find it. I tried using wal Mart brand but I swear my motor either burn it,or spit it out

$26.83 Gal. @ Walmart
 

Mobil 1 5W-40

I've just switched over to mobil 1 10-40 synthetic for our cars... one with a 103 and the other with a 104.

i had used diesel oil for years...but quite frankly...i want to change the oil half as often...

yeah I got to reading one day what royal purple had in it for racing.Then found out diesel oil had more calcium,and phosphorus, and zinc.Our 1960s oil was good till they changed to cats.I have no cats so,I run a better oil.I change at 5000 miles, if 15w40,and 5w40 10,000 miles with filters changed at 3000 miles

My service manual says change every 7500 miles. I am going towards the shell Rotella brands (15W40) and I will still change every 3000. Any takes on this?

I change my oil in the spring, and in the fall. I have always used rotella.

Why?

its up to you,but is using dieseo oils better to get 5,000 miles at least.

I did a boat load a research and 15w40 is a great choice. I called a shop who rebuilds all Benz and the man I spoke to said synthetic oil cannot properly lubricate the 103 &104 design. He said he has seen this problem so many times where people use synthetic and the cams go up in smoke eventually. So it is better to run the diesel grade oil. If you want more protection in colder climates, simply switch to a lighter weight. NO WONDER WHY THESE AWESOME CARS CAME WITH 15W40 FROM THE FACTORY!!! :)