[dieter]

I have a 2002 TD5 and used Mobil one 0W40 standard. I was told that this oil is suitable for Turbo Diesel engines. What about the Mobil one 0W40 Turbo Diesel oil? Shouldn't I have used this instead of the standard Mobil one?

 

[Funrover]

Wow..that is thin oil...... In my diesel car I run mobil one sythetic 15w-50.... Have for years...car has 500,000 miles and still going strong...

 

[Geoff]

Jeep recommends Mobil 1 0w-40 in the US for their CRD Liberty, possibly because it is commonly available. Check the bottle for an API CH-4, CI-4, or CI-4+ rating (best). Generally speaking, Mobil Delvac 1 5w-40 (CI-4+)is better. It is designed for diesel engine use and has a much more robust additive package that will protect parts in "boundary" conditions, where the oil has run thin. In the US it is also sold as Mobil 1 Truck and SUV.

If the TD5 has a traditional non-roller cam in particular, then go for the Delvac. The other reason for higher viscosity requirements in diesels is that they have about twice the compression of gasoline engines and run at low rpm, high loading. Both put a lot of loading on the main and rod bearings.


Multi-viscosity oils are non-Newtonian, meaning they shear a bit under certain conditions. A higher base (15w- vs 5w-) may be better for the TD5 if it has larger oil passages and is otherwise designed with thicker oils in mind.

All of the standard diesel oils have excellent chemistry and are designed to hold up under commercial use: Shell Rotella, Chevron Delo, and Mobil Delvac. All of these are in 15w-40 grades and work fine in turbo applications. I use Shell Rotella in my 4.6 as it is also SL rated for gasoline engines (in the interest of protecting the non-roller cam lobes).