Difference: Car and truck diesel engine oils?

[LucasDK]

Hi,

I've asked this question in other forums but have never gotten any good answers.

2 Questions:

1. What is the difference between a truck diesel engine oil (heavy duty probably) and a car diesel engine oil (normal duty probably)?

2. Should I avoid using heavy duty engine oils in normal passenger diesel cars (of course observing viscosity requirements)? And why?

From reading about standards I've concluded the following:

MB228.XX series is for heavy duty engines
MB229.XX series is for light duty engines (passenger cars)

ACEA EX series is for heavy duty engines
ACEA AX series is for light duty engines (passenger cars)

API CX series does not not distingguish between heavy duty and light duty engine oils

Please correct me if I'm wrong.

From reading the ACEA standards the only main difference between EX and AX series is the ash content - it has a higher threshold in EX series. Also something about foaming capabilities as I remember.

ACEA Standard

Furthermore I see that AX series are tested for different properties than EX series.

Maybe somebody can enlighten me .

Lucas

 

[dparm]

Countless folks on here run the heavy-duty oils in passenger cars without any issues. Just look up Rotella T6 on here, for example...

 

[Radman]

My company spent two years and a chunk of cash to figure out what would be the most cost effective oil. Long story short Rotella 15W40 mineral is what they use on everything. I have seen the reports and I can not argue. In fact once my synthetic stash is consumed I will be going with Castrol 5W30 GTX. No reason for me to spend more than I have to for similar results.

 

[ahoier]

I was under the impression there was no difference between HDEO's for passenger cars, and say pick up trucks.

All the same. As far as the "standards" and "specs" that's hard to say, as I browse the oils down the oil aisle, the "donut" on the back of the bottle has various ratings from 1 oil to the next. But most all of them meet "SM" rating.....

The only thing I'd be worried about is running the "heavy" oils in a passenger car....but then again, a friend of mine at the TLE department says they got a taxi company that brings their Ford Freestar and Econoline van in at least once a month for an oil change, and always put 20W-50 in it....lol.

 

[m37charlie]

there are quite a few differences both in lab requirements and test-stand requirements. An example: ACEA A1/B1 and A5/B5 call for HTHS 3.5.
One should use what the mfg recommends unless you have a good specific reason not to. However, I really like Mercedes' recommendations:
http://bevo.mercedes-benz.com/bevolistenmain.php?session_id=&navigation_path=&language_id=1
Sheet 223.2
For most of their gas engines and car diesels, Mobil 1 0W40 is perfect.
For DPF car diesels, they allow a 228.51 low ash truck diesel like Delvac 1 LE 5W30. But be careful: they don't approve the ubiquitous 228.31 oils (CJ4) in DPF car diesels - too much phosphorus!
http://www.mobil.com/Italy-English/Lubes/PDS/GLXXENCVLMOMobil_Delvac_1_LE_5w30.aspx
in place of the weak (in TBN/detergency) 229.31/51 oils
Running the wrong viscosity (too low) can be a big lube problem in warm weather. Running too high a viscosity can be a problem particularly if there is an oil driven pump like an HPOP or VANOS. And of course poor lubing with cold starts.
Also: Cx is ACEA, not API. It is low ash/P/Zn for DPF/catalyst equipped cars - diesel. NOT trucks. E6 and E9 are for DPF/catalyst trucks.
Just my opinion.

Charlie

 

[yannis]

The differance is the amount of additives they use, which can be corrosive or form harmful deposits .
Therefor you shouldn't use ACEA Ex in applications that require ACEA Bx.

 

[Rollins]

These are the current ACEA (2010) Oil Sequences:
http://www.atiel.org/members/pdf_files/2010-12-13 ACEA Seq.pdf


Another important difference is the duration of the shear stability test (90 cycles for E6;E7;E9 oils, opposed to the 30 cycles for ACEA Ax/Bx and Cx oils)
http://www.swri.edu/4org/d08/global/ShearStb/default.htm

Some engine manufacturers’ demands might be even higher (Volvo VDS-4 category, which usually goes along with ACEA E9 and CJ-4, demands after-shear HT/HS visc. >3.9cP for SAE XW-40 …the test method ASTM D7109 however differs to ASTM D 6278 in test sample quantity-200ml. instead of 175ml. for D 6278)
VDS-4


This is an interesting comparison of oils treated with different types of VII and submitted to the shear stability test:
http://hrcak.srce.hr/file/37720

On a sidenote...I'm not sure how accurate is to name MB 228.X a "truck" category...the so-called "passenger" (gasoline-diesel combined) 229.1 was introduced in 1996 or 1997 !!!and to a greater extent founded some of the ACEA Ax/Bx specs. The manufacturer still recommends 228.x oils (228.5 or mostly 228.51) for their modern PC & light duty trucks diesel engines.