Which Motul?

[Brit33]

Was recently using Castrol TWS but it is not commonly available here so need to go back to MOTUL.

Just put in some 300v 15w50 as I had it stored away as surplus.

comparing this with the other motul oils such as 6100 15w50 semi and 5w40 X-cess I'm not sure what to stick to.

mine is the alfa romeo 1.7 1988 double carb boxer engine. runs quite rich on its idle circuit.
High revving with flat hydraulic tappets.

April-Sep (winter): mainly short trips in the city (0-10c average temp)
Oct-March (summer): long weekend trips (25-40c average temp)


should I go back to the semi 6100 15w50?
or even try the thinner 5w40 X-cess?

(there is always Mobil 5w50 as an alternative to the Motul, widely available)

Thanks

 

[dparm]

Just curious, why were you running such thick oils? What is the manufacturer oil requirement?

 

[Brit33]

I knew I'd get that question. Lol

manufacturers recommend oil is 10w50 (agip 10w50 in 1988 no longer made).
Always used a 50wt oil and once a light 10w60.

10 psi @900 rpm (notoriously low at hot idle, big ends and mains ok)
40 psi @2200 rpm
50 psi @3200 rpm
60 psi max @ 4000+ rpm

bypass opens at 88 psi

hot at 100c (cruising at 120kmh for extended periods. )
85-90c in town driving

 

[dparm]

Have you ever tried one of the more stout 5w40s such as Red Line or Motul 300V? Those are very thick for their grade and behave more like a 50.

 

[Brit33]

Originally Posted By: dparm
Have you ever tried one of the more stout 5w40s such as Red Line or Motul 300V? Those are very thick for their grade and behave more like a 50.


Redline is not imported here.

I'm trying to see if there is one of the 40wt 300v oils.
maybe the 5w40 or 10w40 300v?

 

[dparm]

Originally Posted By: Brit33
Originally Posted By: dparm
Have you ever tried one of the more stout 5w40s such as Red Line or Motul 300V? Those are very thick for their grade and behave more like a 50.


Redline is not imported here.

I'm trying to see if there is one of the 40wt 300v oils.
maybe the 5w40 or 10w40 300v?


The 5w40 300V is pretty good. The formula was recently updated as part of the "Ester Core" change. The HTHS is 4.1.

The 10w40 is only HTHS of 4.2, so it's barely any thicker.

 

[Brit33]

Originally Posted By: dparm
Originally Posted By: Brit33
Originally Posted By: dparm
Have you ever tried one of the more stout 5w40s such as Red Line or Motul 300V? Those are very thick for their grade and behave more like a 50.


Redline is not imported here.

I'm trying to see if there is one of the 40wt 300v oils.
maybe the 5w40 or 10w40 300v?


The 5w40 300V is pretty good. The formula was recently updated as part of the "Ester Core" change. The HTHS is 4.1.

The 10w40 is only HTHS of 4.2, so it's barely any thicker.


10w40 would be more shear stable wouldn't it?
But I see the VI for 5w40 is much higher hmmm

 

[Brit33]

Just found this in the specs of X-cess 8100:
"
The FIAT 9.55535-H2, M2 and N2 performance levels impose the engine oil to combine both ACEA
A3/B4 standard and 5W-40 viscosity grade in order to perfectly lubricate most of the Gasoline and
Diesel engines of FIAT, ALFA-ROMEO, and LANCIA produced before July 2007"

But it has a fairly low HTHS of 3.7.
I can see my OP dropping at idle with this.

 

[dailydriver]

I would use the 300V 5W-40 in the winter, and the 300V 15W-50 in the summer, or some blend of the various 300Vs if you are open to mixing.

 

[Brit33]

Originally Posted By: dailydriver
I would use the 300V 5W-40 in the winter, and the 300V 15W-50 in the summer, or some blend of the various 300Vs if you are open to mixing.

Sounds good to me.
Open to mixing the 300v oils.
Could try half and half to see how low the op goes.
May get away with a 5w40 but a step at a time.

I know the recent oci was too long as I had to clean sludge out of the pan.
That was using castrol after 15 months and half way through the winter now.

 

[dparm]

I think the 5w40 could serve year-round duty just fine. In service, it is basically as thick as a 50.

 

[Brit33]

Originally Posted By: dparm
I think the 5w40 could serve year-round duty just fine. In service, it is basically as thick as a 50.


Do you know if I'd see much of a drop in op from the 15w50?
Or would the extra flow benefit the engine more? I keep reading that as long as you have 10psi per 1000 rpm you are fine.

Thanks

 

[dparm]

The 300V 15w50 (new Ester Core) has HTHS of 5.3, meaning that at operating temps it could be up to 23% thicker than the 5w40. But again, we don't know if that's even necessary.

Also remember that back when that oil was spec'd, oils were not as good as they are today. 300V is extremely shear-stable, meaning that by the time you go to change it the viscosity should be very close to what it was when new. In 1988, a 10w50 would probably have dropped down to a 10w40 or worse.

By the way, your oil temps are not that high. 100C is fairly typical for a modern vehicle. A thinner oil will actually drop those temperatures a bit.

 

[Brit33]

here we go.
this is what they have locally in the 40wt category

300v 5 w 40
300v chrono 10 w 40

the 10w40 is marginally cheaper.
around 100 usd for 4 litres. pretty standard here for 300v.
8100 X-cess is around 70 USD but for 5 litres

 

[Brit33]

also just read this:

https://bobistheoilguy.com/forums/threads/motul-300v-5w40-vs-10w40.176417/

I've looked at the Motul website recently and remember the 5w40 oil being API SL and the 10w40 being API SG. This means that the 10w40 will have more zinc and phosphorus...and that's a good think in that rocket ship you bought. Further the 10w40 should have less, or no, viscosity index improvers, meaning it will shear less. My vote is for the 10w40.

 

[Brit33]

also can these 300v oils be run for 12 months? or just 6 months

 

[Brit33]

inclined to go for the 300v 10w40.

good cold start up lubrication and a thick 40wt probably better than the X-cess.
I don't do more than 5000 kms a year so will be changed at this interval unless its advised to change the 300v twice a year.