What is the better synthetic diesel oil?

[RateNate]

I've been pretty happy with Mobil Delvac 1 ESP, in 5W-40 flavor. It's more robust than the Mobil1 TDT 5W-40. Using it in almost everything, from 1.4L T-Jet Fiat to a 6.7L Cummins Ram. Plenty of high RPMs, and never any oil-related issues.

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Yeah I was looking at their 15w40 flavor but I noticed T6 had a 20c degree higher flashpoint….

 

[vronline00]

I've been pretty happy with Mobil Delvac 1 ESP, in 5W-40 flavor. It's more robust than the Mobil1 TDT 5W-40. Using it in almost everything, from 1.4L T-Jet Fiat to a 6.7L Cummins Ram. Plenty of high RPMs, and never any oil-related issues.

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Not disputing, but just curious how ESP is more robust than TDT? They look almost identical to me.

 

[GR_CoB]

Not disputing, but just curious how ESP is more robust than TDT? They look almost identical to me.

Very close, yes. But over the years there have been a few reports of TDT shearing a bit more.

It is worth noting that most Mobil oils are known to shear initially more than every other oil. There are theories that such shear is done intentionally and doesn't affect performance of the oil, but does help with fuel efficiency. Take it all with a grain of salt. I'll gladly use both, but if I know there will be lots of heavy towing - ESP goes in for my engines.

 

[Wizz]

The Mobil Delvac Extreme 15w-40 synthetic gave me great oil analysis on my Ford 6.0 diesel. Never exceeded 6 ppm of iron on the 5k mile samples I took. And it is dirt cheap at Walmart. One of the few shelf diesel oils with over 1,100 ppm Zinc and Ph.