Molygen New generation 5w-50

[Andrea7]

Waiting for a new oil pressure sender, I'm starting to investigate about what kind of oil should be better to use on my speed six.
Now I use a "simple" Shell Helix Hx6 10w40.
I choosed this oil on the first service cause I thought was a good idea to test the behaviour of the engine on a "normal" oil.

After my possible problem about pressure I started to study a little to find a good oil which could be thin at cold temperature to help the fast lubrication of finger followers but thick on higher temperature to help good pressure and lubrification to all components.

I readed a lot of specs sheets and I found an oil which seems really good on paper: 5w50 Liqui moly Molygen.
There is an old and a new version.
The new it's obviously better but even the old one it's good.



What do you think about?
Any of you use it?

[nawarne]

Morning Andrea.
I would comment that the TVR service folks here in the UK seem to stick with the Mobil oils as recommended by TVR back in the day.
I've not heard any reports of the Moly oils.
I think any 'good' quality product from a well known oil producer wont let you down. I used to work for Exxon-Mobil, and their synthetic lube oil base stock was used by several of the big names (~ 20 years ago!!)

Nick

[Byker28i]

I use Mobil 3000 5W40 in the AJP because thats what Str8Six use/said to use when they rebuilt my engine.

[jstx]

@Andrea7, the only real way to know is with an oil analysis - and even those, done wrong, can be misleading. The true way to do one is to change the oil 2x with the new oil, then capture a small sample to send off for analysis.

Even manufacturers recommend the wrong oils - just see the GM debacle going on right now with the L78 V8 engines. Manufacturers recommend different oils with the same engine depending on the country's emission requirements too, so take their recommendation as a starting point. Send in the analysis and get the data for your engine and for your use.

I'm sure you have testing labs in your area, we are spoiled to have many here in the States. There is a plethora of information out there in this field. This is a good place to start - https://www.youtube.com/@themotoroilgeek

This was a fantastic question & answer session, really long but fantastic. he has some very good videos on his channel
https://www.youtube.com/live/mr07y1H3U7c?si=lFBuzs...

Edited by jstx on Thursday 8th May 17:30

[keynsham]

I had a friend who's father worked for Duckhams some years ago and his view on oil was simple. Basically all engine oil is created from a base oil with additives to bring it to the relevant specifications. Benefits of synthetic is that the base oil is synthetic and so will last longer without beginning to break down. But property-wise it is the same as supermarket cheapy oil when it is first poured into your engine. If you change your oil every 1000 miles then it doesn't matter what you put in. If you change it at 15000 mile intervals like some modern cars then more expensive synthetic is a must. I generally pick something in the middle. Oil is like any other product and is priced not on cost but on popularity and advertising. Is Mobil one really worth £75 for 5 litres when an oil half the price will do just as well? It is a very personal choice but in reality it is all cheap compared to an engine rebuild!!

I have just bought a Mercedes and they don't even recommend any oil brands, just a table of viscosity against environmental operating temperature range, which basically means anything from 0W30 to 20W60 is ok!!

[Andrea7]

Quite agree with all you say....BUT...

Engines and environment are not always the same.
Specs and year of construction of an engine may vary a lot and change what you need from the oil.
Country whether and kind of use (road/track) may have an influence too.
As far as simple my thinking should be, I think that viscosity and shear resistance are really important factors and, on speed six in particular, cold and hot viscosity are key factors.
The first act on the wear of finger followers, the latter on the kind of protection offers on engine moving parts and on engine oil pressure
And this it's the reason I found this oil interesting.
Has similar specs to the old Sylkolene (now Titans Fuchs) which it's almost impossible to find in Italy and consider one of the best on the Speed Six

Edited by Andrea7 on Friday 9th May 07:36

[keynsham]

Agreed. The range of oils given for my Mercedes covered hot to cold climates so you need to choose the one suitable for your environment and not just pick one from the list. And I wouldn't put cheap supermarket oil in any of my cars either. it may, and most likely is, absolutely fine if changed regularly and also probably comes form a big oil company anyway but why take the risk for the sake of an extra twenty quid!!!

[Imran999]

I’ve been scared away from using Mobil 1 (and switched to Liqui Moly).

My old 911 engine (history of 2000 mile oil change intervals, with Mobil 1 as recommended by the manufacturer) suffered from premature bearing wear. The specialist who rebuilt the engine for me, explained that Mobil 1 is highly ineffective when combined with moisture. Unfortunately, I wasn’t using the car very frequently and so moisture in the oil was a factor.

They recommend Liqui Moly.

I switched the Cerb over as well and I have to say, just listening to the cam-clatter (when cold), it was already quite minor (2001 engine, 6000 miles), but now it’s reduced to almost zero.

I’m no expert, just some anecdotal input.

[Andrea7]

What oil are you using?

[jstx]

Mobil 1 15W-50, it has 1300 ppm of zinc which is good for flat tappet engines. I know TVR recommended 0W40, but I wasn't comfortable with the wider difference between low and high # viscosities because that can lead to a thinner oil film under high shear conditions, so I'm trying the 15w-50. I was going to go 20w-50 but that has much higher zinc content which I felt like is unnecessary.

That said, this is my first oil change so I have not sent a sample off for analysis. I will definitely be doing that in the future to see how that oil is doing.

[Byker28i]

Imran999 said:

I’ve been scared away from using Mobil 1 (and switched to Liqui Moly).

My old 911 engine (history of 2000 mile oil change intervals, with Mobil 1 as recommended by the manufacturer) suffered from premature bearing wear. The specialist who rebuilt the engine for me, explained that Mobil 1 is highly ineffective when combined with moisture. Unfortunately, I wasn’t using the car very frequently and so moisture in the oil was a factor.

They recommend Liqui Moly.

I switched the Cerb over as well and I have to say, just listening to the cam-clatter (when cold), it was already quite minor (2001 engine, 6000 miles), but now it’s reduced to almost zero.

I’m no expert, just some anecdotal input.

IMS bearing?

[Imran999]

Byker28i said:

Imran999 said:

I’ve been scared away from using Mobil 1 (and switched to Liqui Moly).

My old 911 engine (history of 2000 mile oil change intervals, with Mobil 1 as recommended by the manufacturer) suffered from premature bearing wear. The specialist who rebuilt the engine for me, explained that Mobil 1 is highly ineffective when combined with moisture. Unfortunately, I wasn’t using the car very frequently and so moisture in the oil was a factor.

They recommend Liqui Moly.

I switched the Cerb over as well and I have to say, just listening to the cam-clatter (when cold), it was already quite minor (2001 engine, 6000 miles), but now it’s reduced to almost zero.

I’m no expert, just some anecdotal input.

IMS bearing?

Actually it was a main bearing :-(

[jstx]

There's no one perfect oil for all applications, to believe so is just falling for marketing hype, and I know enough about Tribology to spell it, but I'm not putting any oil in any of my engines where the oil company does not provide easy access to simple product data sheet information.

[Andrea7]

Motul 8100 5w50 seems a real good product also.
And, here in Italy, has a good price also...

[Andrea7]

Only for comparison, here the Shell Hx6 10w40 I have now:



Note that, compared to Motul or Liquimoly 5w50, She'll has a lower viscosity even when cold.
Quite sure it depends from the synthetic base oil quality and additives.
Viscosity index is really lower also...

[jstx]

Your "old" Shell Hx6 10w40 oil starts with a lower base viscosity (40) vs the new Liqui Moly 5W-50 (50) so that's to be expected. The first number represents the "winter" conditions, the second number is the base viscosity; in this case 40 vs 50. There are only a few different companies that sell base oils, the important bits are what is in the additive package(s). Most every other company makes it very easy to see what is in their product(s). I want to see how much Phosphorus, ZDDP (Zinc), the company's recommended application for that oil as well as the viscosities at temp(s).

The AJP is a flat tappet engine so needs some zddp and phosphorus, but not crazy amounts either. I'm not looking for anything with 1700ppm or something with 600ppm either; too much zinc, can cause pitting of the metals inside your engine, not enough and you'll experience tappet and or camshaft wear.

For an engine with a flat tappet cam, I want an oil with at least 1,000 ppm ZDDP and a phosphorus level at least 900. That should provide the minimum protection. That's why I chose the 15w-50 Mobil 1 as it has 1300ppm ZDDP and 1200 phosphorus; not too little and not too much; same base oil viscosity as yours at 50. As I said, I will be running an oil analysis so we shall see if it is up to the job of an AJPV8

[Andrea7]

jstx said:

Your "old" Shell Hx6 10w40 oil starts with a lower base viscosity (40) vs the new Liqui Moly 5W-50 (50) so that's to be expected. The first number represents the "winter" conditions, the second number is the base viscosity; in this case 40 vs 50. There are only a few different companies that sell base oils, the important bits are what is in the additive package(s). Most every other company makes it very easy to see what is in their product(s). I want to see how much Phosphorus, ZDDP (Zinc), the company's recommended application for that oil as well as the viscosities at temp(s).

The AJP is a flat tappet engine so needs some zddp and phosphorus, but not crazy amounts either. I'm not looking for anything with 1700ppm or something with 600ppm either; too much zinc, can cause pitting of the metals inside your engine, not enough and you'll experience tappet and or camshaft wear.

For an engine with a flat tappet cam, I want an oil with at least 1,000 ppm ZDDP and a phosphorus level at least 900. That should provide the minimum protection. That's why I chose the 15w-50 Mobil 1 as it has 1300ppm ZDDP and 1200 phosphorus; not too little and not too much; same base oil viscosity as yours at 50. As I said, I will be running an oil analysis so we shall see if it is up to the job of an AJPV8

This doesn't correspond exactly to what I know:

Kinematic viscosity measured at 100°C defines SAE grades from 20 to 60 for increasing viscosity values.
Dynamic viscosity at low temperature defines SAE "W" grades from 0W to 25W based on viscosity values measured at temperatures from -35° to -5°C.
The temperature represents the minimum at which the engine can be started when it is lubricated.
Here a chart which explains easier what I mean:



So, as I told you, it's strange that a 5w it's more viscous than a 10w at low temperature but it's probably explained by the fact that the first is synthetic and the latter isn't (of course additives are important too).

About ZDDP: for what I know it's an additive which reduce wear of components which are in contact.
So, rather than looking the amount of ZDDP, I think it's important to look at the HTHS value which it maybe could be more exhaustive.

Edited by Andrea7 on Wednesday 14th May 08:57

Edited by Andrea7 on Wednesday 14th May 09:10

[jstx]

I found this, where a certified tribologist walks you through making a certified sellable oil from start to finish. This same guy invented Driven Oils.
https://youtu.be/57ubgGVkCF8?si=falyVe4WUDHVKeqn