Which Mobil1?
Thread Starter
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
It's a great oil (Mobil1 0W40).
You have to get past the "The handbook says 5w-30" mentality to really pick the oil right for you. Nothing wrong with going with the handbook, it still a good general statement. But one really has to look at your driving/usage habits, climate, and assess an oil based on it's specs before passing judgement.
The 0W-40's Viscosities at 40c/100c (which place it around a light 40w) are fantastic, and after the VII shear down it starts to perform like a heavy 30w. With an outstanding HTHS of 3.8, it's one of the highest among the heavy 30/light40 weight oils I've looked at. The additive package with a high TBN and high zinc/phos is great. Plus the price is right.
My buddy is actually running a blend of M1 0w-40 and 15w-50 in his Porsche 911.
You have to get past the "The handbook says 5w-30" mentality to really pick the oil right for you. Nothing wrong with going with the handbook, it still a good general statement. But one really has to look at your driving/usage habits, climate, and assess an oil based on it's specs before passing judgement.
The 0W-40's Viscosities at 40c/100c (which place it around a light 40w) are fantastic, and after the VII shear down it starts to perform like a heavy 30w. With an outstanding HTHS of 3.8, it's one of the highest among the heavy 30/light40 weight oils I've looked at. The additive package with a high TBN and high zinc/phos is great. Plus the price is right.
My buddy is actually running a blend of M1 0w-40 and 15w-50 in his Porsche 911.
I can see why it would be a good choice for a modded car, or for the track, where oil temperatures could be in excess of 120C (248F). The viscosity of a SAE 40 oil at 120C is 8.8cst, which is very similar to the viscosity of the factory recommended SAE 30 operating at 100C (212F), that has a value of 9.3cst
You point out a very significant detail: if, when the Viscosity Index Improvers wear down, it starts to perform more like a SAE 30, then it's still the equivalent of a fresh 0W30!!!
Going back to the Mobil1-5W30 High Mileage, do you think that the fact that it has extra cleaning additives and seal conditioners could adversely affect "low mileage" engines?
Team Owner
Joined: May 2001
Posts: 25,057
Likes: 1,265
From: Virginia
St. Jude Donor '11
...Me too....Mobil 1 10W30 
