Visccosity of 0W40

[Roger3116]

Please help me understand. If I am reading the specs correctly, the cSt@ 100c of Delvac 1300 15W40 is 15.6, and the cSt @ 100c of ESSO XD-3 OW40 is 15.7. I think this means that the ESSO is slightly thicker when the motor is at running temp. Why is it then that the Esso has 5lbs "LESS" oil presure than the Delvac? Should they not be about the same? I switched to the ESSO synethic for the winter and was very perplexed to find the oil pressue less right across the operating RPM. Can anyone explain? Roger

 

[Gene K]

At what oil temp?

Basically the oils are the same viscosity at 100&#176C.

The Esso is definately thinner at Cold Cranking Test Temps.

If I was guessing I would say your sump temp is only 70-80&#176C and the Esso Oil is thinner at that temp.

Maybe you could get the 40&#176C Viscosities and compare?

Edit:
Delvac 1300 15W-40 = 123 cSt @ 40&#176C
Esso XD-3 0W-40 = 94.5 cSt @ 40&#176C

Gene

[ October 03, 2004, 03:44 PM: Message edited by: Gene K ]

 

[Roger3116]

The engine runs between 190 & 200F once it is up to temp. and stays there for the day. If I stay under boost for a long time it will go to 205-210 and the ESSO drops 2-3psi. I do not know what the oil temp is but I would guess it is around 200F. The ESSO is definitly thinner at 200F than the Delvac. Roger

 

[Cyprs]

I have used a Tech2000 semi syn 15-40 and a 0-40 Co-op DMO full syn oil Roger 3116, Compared to any dino 15-40 I have used I find less oil pressure with syn or syn oil/blend in my 92 Cummins Dodge.

I questioned A mechanic with my low oil pressure concern, he explained to me that syn oil has more flow, with syn oil the bearings get more volume of oil but there will be less pressure because of syn's better flow property.

I am now using 15-40 XD3, as soon as the weather turns cold or my kms are up for next OCI, I am going with the XD3 0-40 syn oil with no fear.

Cyprs

 

[Cyprs]

Forgot to mention, I am going to use XD3 0-40 all year round and it gets up to 40C or 100F above in summer here. One Esso bulk agent uses 0-30 XD3 syn oil all year round in his recent cummins dodge. Esso tells me no problem using 0-40 all year, he also tells me that many people having oil cunsumption problems with dino who switch to this 0-40 have little to no more oil consumption. Esso stands behind their products, they dont tell me these things with hollow claims or B.S. in my opinion. When a bulk agent puts 0-30 XD3 year round in his own 2001 Dodge Cummins in this hot summer climate, I too have to believe in this 0-40 for winter and summer year round use.
Cyprs

 

[olympic]

Put simply, the XD3 is thinner than the Delvac at all temps below 100C, that's what's causing the reduced oil pressure. A few PSI is nothing to worry about, you're still getting the same gallons per minute of oil flow, the XD3 just needs less PSI to achieve it.

 

[Cyprs]

Yeah Roger3116. what Olympic said but more consisely than my posts, just trying to ease your mind on this oil pressure, it really concerned me too at one point, these are expensive engines.

Olympic, I just put this 0-30 XD3 in my Altima, great quick flow, that engine started this morning at 0 C like a 40C afternoon, absolute instant flow. I cant wait to get this XD3 0-40 in my diesel. Right now with 15-40 dino on a cool fall morning that oil pressure guage is slow.

Cyprs