Whos running Mobil 1 0w-40?

[dparm]

Originally Posted by Killerfish2012

Speaking of BITOG, there was a guy on there who switched from Castrol 10W60 to M1 0W40. He only did mild "canyon cruising" and no track driving. His S65's lead levels dropped as we have become accustomed to seeing, but at only 3,000 miles, KV 100 had gone almost below Mobil's range, and his other wear metals made a dramatic jump up. Blackstone advised him to ditch the oil by 5K miles Max! He stayed with Mobil 1, but then started using an oil additive. For me this was enough evidence to show why the engineers specified 10W60. Whether or not they knew about the bearing wear is anyone's guess, but they clearly had the evidence that showed increased wear to other engine metals with thinner oils. This is why I settled on Total 10W50. I think it's ok to advocate the use of M1 0W40, especially for folks with high lead, or who have been using the Castrol, but we need to stress that the oil change interval must be sooner, and that any hard track use has to be minimal.

Shearing isn't a bad thing and is not a reason to panic. Read more on BITOG and you will understand why.

[SenorFunkyPants]

Is there a specification or a measurement of "film strength" for these oils?

[dparm]

Originally Posted by SenorFunkyPants

Is there a specification or a measurement of "film strength" for these oils?

Not really. Amsoil likes to parade one around but it has been disproven as not representing real four-stroke engine conditions.

It can be broadly inferred based on additives and basestocks.

[SenorFunkyPants]

It seems to me that picking an alternate oil based solely on its viscosity is a bit random (and risky)....they are all going to flow at a similar rate.
Some measure of film strength is surely far more important...not much good in having a lighter weight oil just for the sake of it, you need to know how resistant it is to high loads like in the cam lobe - hydraulic lifter area.

[dparm]

Originally Posted by SenorFunkyPants

It seems to me that picking an alternate oil based solely on its viscosity is a bit random (and risky)....they are all going to flow at a similar rate.
Some measure of film strength is surely far more important...not much good in having a lighter weight oil just for the sake of it, you need to know how resistant it is to high loads like in the cam lobe - hydraulic lifter area.

They only flow at the same rate through the pump. As soon as it leaves the pump everything is different.

As I've said for a long time, HTHSV is the best indicator of operational viscosity that we have (it's because oil will easily hot-spot to 150 C in the bearings and other areas).

[SenorFunkyPants]

Originally Posted by dparm

They only flow at the same rate through the pump. As soon as it leaves the pump everything is different.

Ok so lets say we are designing the lubrication system for the S65.
After running all the numbers, models, simulations and test engines it is decided to go with the Castrol 10W60 and that the target oil flow rate at the bearings is 10 gallons/minute @ 212F @ 90 psi @ 6k rpm and we set the oil pressure relief valve accordingly at 95 psi. Fluid dynamics is another planet to me so for the sake of argument lets say that to achieve the target we need the volume flow controlled oil pump to output 11 gallons/min @ 212F @ 90 psi @ 6k rpm.
So whats the effect of changing the oil to 0W40? The oil pump will still output at 11 gallons/minute but now at say 80 psi - how will this translate at the bearing interface? If its the same 10 gallons/minute then there is no advantage to using this oil in terms of flow rate, if its higher or lower then it is no longer at the optimum target flow rate.

[Petros]

Flow rate of any fluid is proportional to the surface area of the conductor and inversely related to the viscosity. The first one cannot really be changed, unless you use thinner bearings (none are available in the aftermarket for the S65 engine), or grind the crankshaft lobes a bit like regular guy recommends. The other parameter is what you can influence. By using a thinner visosity you can increase oil flow through the gap between the bearings and crankshaft. Oil, like any fluid, seeks the path of least resistance. So even if the overall flow rate is the same through the pump, it is still possible that the thicker oil doesn't flow through the bearings as much as the thinner oil.

[SenorFunkyPants]

Isn't it sort of self regulating...in the sense that the oil flow rate through the bearing is a function of viscosity and pressure. A 0W40 oil will be at a lower pressure than the 10W60.

[dparm]

Originally Posted by SenorFunkyPants

Isn't it sort of self regulating...in the sense that the oil flow rate through the bearing is a function of viscosity and pressure. A 0W40 oil will be at a lower pressure than the 10W60.

Yes, thinner oils generally result in lower oil pressure.

[Petros]

Originally Posted by SenorFunkyPants

Isn't it sort of self regulating...in the sense that the oil flow rate through the bearing is a function of viscosity and pressure. A 0W40 oil will be at a lower pressure than the 10W60.

It's not really my area of expertise so I'm not sure. But it's possible the relationship is not as simple and linear as you think. Perhaps the improved flow as a result of lower viscosity is greater than the reduced flow as a result of less oil pressure. If that's the case then a thinner oil will lead to better flow even with the reduction in oil pressure.

[dparm]

It is not linear. Multi-grade oils are non-Newtonian fluids.

[Killerfish2012]

Originally Posted by dparm

Yes it is.
Mobil 1 is a streetable race oil -- even Mobil says so. Go to the Mobil 1 website and they list the 0w40 in the same category as Mobil 1 Racing 0w30 & 0w50. The 0w40 is also a spec oil in several racing series that's used right out of the bottle. It is truly their halo product and there are countless people using it in track cars.

I finally looked into this and found the following: Mobil 1 0W40 :"Mobil 1™ 0W-40 is an advanced full synthetic motor oil designed to help provide exceptional cleaning power, wear protection and overall performance. Mobil 1 0W-40 keeps your engine running like new in all driving conditions."

Mobil 5W50: "Mobil 1™ 5W-50 synthetic motor oil has race-proven technology and is suited for extreme driving conditions and motorsport applications. In racing or normal driving, Mobil 1 5W-50 (Rally Formula) helps provide heavy-duty engine performance and protection for an outstanding driving experience."

Clearly mobil intended their 0W40 for street use, and their 5W50 formular for racing. Oddly enough, Mobil 1 5W 50, and Total racing 10W50 have almost identical specs. I will be switching to mobil 5W50, and will be using this oil year round, including summer track days. It's much much cheaper than the total, which is a plus!

[dparm]

I think you'll see a lot more shearing and poor cold start/cold weather performance with the 5w50.

[kawasaki00]

Originally Posted by dparm

I think you'll see a lot more shearing and poor cold start/cold weather performance with the 5w50.

True statement. Have tested the 5-50 and it does not hold viscosity as well as the 0-40. At 100f 0-40 flows 25% better

[Leonardo629]

M1 5W50 is not as readily available as 0W40 Euro formula, let us know when you are able to source the M1 5W50

[dparm]

Originally Posted by Leonardo629

M1 5W50 is not as readily available as 0W40 Euro formula, let us know when you are able to source the M1 5W50

He could always mix the 15w50 and 0w40 -- would give him a heavy 40, but still dilutes the already excellent 0w40.

[Leonardo629]

Just checked out the spec on the 5W50, it's nearly 30% heavier than the 0W40 at operating temperature and almost 45% heavier at cold start. You might as well just run 10W60 Edge Pro at that point.

[Killerfish2012]

Originally Posted by Leonardo629

M1 5W50 is not as readily available as 0W40 Euro formula, let us know when you are able to source the M1 5W50

It's at NAPA auto parts for 5.99 per quart!

[Killerfish2012]

Originally Posted by Leonardo629

Just checked out the spec on the 5W50, it's nearly 30% heavier than the 0W40 at operating temperature and almost 45% heavier at cold start. You might as well just run 10W60 Edge Pro at that point.

Again, you mavericks gotta watch it with 0W40. The viscosity is WAY different than oem. While it's certainly much easier on the bearings (lead), all these other high wear metals indicate accelerated wear on other engine parts. Unless strictly low oil change intervals are observed with this oil, you guys are asking for it.

[kawasaki00]

Originally Posted by Killerfish2012

Again, you mavericks gotta watch it with 0W40. The viscosity is WAY different than oem. While it's certainly much easier on the bearings (lead), all these other high wear metals indicate accelerated wear on other engine parts. Unless strictly low oil change intervals are observed with this oil, you guys are asking for it.

There are in eccence no wear elements in this engine other than bearings and rings.

[SenorFunkyPants]

Originally Posted by kawasaki00

There are in eccence no wear elements in this engine other than bearings and rings.

And cam lobes?

[kawasaki00]

Originally Posted by SenorFunkyPants

And cam lobes?

Not really, the springs are so light on most engines that there is so little wear. Any high quality oil should be sufficient for OHCams. Not saying there have not been a few lobes wiped out but I would guess it is from debris or a improper crown on the bucket or lobe taper. I am sure some of that junky recycled oil from stores could lead to increased wear.
We have noticed that some of the cam chain followers are worn out more than the cams themself. I know VW had a problem with some of the diesel engines wiping out the plastic ( whatever material) followers in their stuff.