Motor Oil Selection - Decision Making Process

[nielkfj]

Thanks to the respondents to my other thread for recommendations on a motor oil for my 2013 GTI.

In this thread I’d like to ask about the primary factors that I should consider when selecting motor oil in the future.

I assume the most important factor would be ensuring that the oil meets the OEM specification (VW 502.00 or 503.00 or 504.00). But what are the other important factors to consider - such as other OEM specs that are listed on the bottle, or specific physical properties of the oil?

For example here are some other manufacturer specs I've seen mentioned:

Porsche A40
MB 229.5
BMW LL-01

And here are some physical properties I've seen mentioned:

NOACK volatility (lower is better)
HT/HS viscosity (higher is better)
Sulfated Ash content (lower is better)
Mini-Rotary Viscometer at low temp (lower is better)

Are there other important physical properties or OEM specification to consider, and how would you rank them in order of importance?

 

[Leo99]

I trust in the OEM to set the specs they think are important. No need to overthink it.

 

[skyactiv]

I don't think higher is better for HT/HS. I don't think it matters as long as it is 3.5 or higher.
I replaced the intake manifold on my GTI around 80K miles and cleaned the intake valves while I was at it. It is not a difficult repair or expensive repair.
The Humble Mechanic has a video on it.
https://www.ecstuning.com/b-genuine-volk...bd/06j133201bh/

 

[oil_film_movies]

Originally Posted By: skyactiv
I don't think higher is better for HT/HS. I don't think it matters as long as it is 3.5 or higher.

HTHS must be greater than X. Higher just means you have more than you need, and fuel economy & cold flow suffers.
The value of "X" is communicated by the manufacturer using the spec they mention. For example, some engines require >2.9, others are at >3.4, etc.
Going with less HTHS than the spec means there could be excess wear, or in severe cases, spun bearings.

 

[1JZ_E46]

Find an oil that meets all 4. VW 502 is generally regarded as the “easiest” of the top 4 euro A3/B4 oil certifications to pass.

Castrol, Motul, and Pennzoil all make oils that meet main 4.

 

[CT8]

The manufactures recommendations are what you want, the rest is going to be sport.

 

[FermeLaPorte]

I would use a German-made oil like Motul or LiquiMoly which what people over there in Germany use

 

[RooflessVW]

Originally Posted By: CT8
The manufactures recommendations are what you want, the rest is going to be sport.

Exactly. Generally, the more specs it meets, the better, but they're all pretty much interchangeable. It's safe to just pick the coolest-looking bottle.

Originally Posted By: FermeLaPorte
I would use a German-made oil like Motul or LiquiMoly which what people over there in Germany use

Motul is French.

 

[edyvw]

Originally Posted By: FermeLaPorte
I would use a German-made oil like Motul or LiquiMoly which what people over there in Germany use

Liqui Moly is average oil at best. Just because it has huge letters that says: MADE IN GERMANY, does not mean it is better then other ones.
Motul is French! Motul did not update its products for like 10 years.

 

[Astro14]

Things to consider:
1. What meets spec for your car
2. What is available

In my neck of the woods, Mobil 1, at $23/5quart jug from Walmart meets the above. And UOA has verified that it works well in my German car.

No need to obsess...

 

[Shannow]

Originally Posted By: Astro14
Things to consider:
1. What meets spec for your car
2. What is available


Too true.

Start with the OEM specs, actually licenced, not meets or exceeds, or recommended for. Actual licence.

Then you are good to go.

Then if the oil you have throws in things like DEXOS, Honda HT-06, ACEA, the Porsche spec then grab them with both hands if it's at your price point.

They are all there because the OEMs found that there was an issue with their kit that "plain vanilla" didn't work with.

When it comes to an API/ACEA spec, they all lobby to have their issue included in the standard raft, spreading the cost over all the bottles sold. If they don't get in, and there's enough of an issue for them, they go it alone, and make their own spec.

 

[kschachn]

Originally Posted By: nielkfj
For example here are some other manufacturer specs I've seen mentioned:

Porsche A40
MB 229.5
BMW LL-01

And here are some physical properties I've seen mentioned:

NOACK volatility (lower is better)
HT/HS viscosity (higher is better)
Sulfated Ash content (lower is better)
Mini-Rotary Viscometer at low temp (lower is better)

Are there other important physical properties or OEM specification to consider, and how would you rank them in order of importance?

Those specifications already specify the other things you mention.

 

[SubieRubyRoo]

Originally Posted By: edyvw
Motul did not update its products for like 10 years.


I've only used Motul Gear 300, but maybe, just maybe, it's possible that their products as they were designed 10 years ago, were forward-looking and well-engineered enough that the 10 year timelapse was just allowing other manufacturers to catch up? SN has been in effect since 2010, so it's possible that if their products were only designed to exceed SN, well, then they haven't necessarily NEEDED a change. All depends on the intended market and what specifications they're looking to meet.

 

[Yah-Tah-Hey]

Originally Posted By: Leo99
I trust in the OEM to set the specs they think are important. No need to overthink it.
There's really not much "overthinking" on the forum Leo. Pray tell where did you come up with such a crazy notion? Regards

 

[BrocLuno]

The HTHS is driven by bearing clearances, sump temps and RPM range. Has your engine been modified? Does it see track days? Do you spend long stretches at redline? Answer yes to any of these and you must make adjustments.

I always start with the Porsche A40 list if track days will be involved

 

[edyvw]

By now NASA could put Space Shuttle back into service.
Get Castrol 0W40 from Wal Mart.