Where did all my oil go? (1 Viewer)

[tarbe]

and now I'm using M1 15W40 with very little oil use again.

Do you mean 5W-40 (T&SUV) or 15W-50?

 

[tarbe]

Oh, and 20W-50 at 10F? No thanks! Not below 40F for me....I love my bearings

 

[RavenTai]

That chart is slightly retarded

5W-30 and 10W-30 oils have more or less the same viscosity at 100C (in fact, I have some 5W-30 Havoline synthetic that is thicker at operating temp than the 10W-30 Havoline synthetic).

So why would 5W-30 only be good up to 50F and the 10W-30 past 100F? Think about it....they are both quite a bit higher viscosity than ideal at start up, and the same viscosity (10 - 11.5 cSt in most cases) at operating temp.

BTW, it is less about whether the oil is 11 cSt (30 wt) or 14 cSt (40 wt) and more about the additive package and the stability of the base oil. It's not just about viscosity...not by a long shot.

Probably has something to do with Viscosity Index Improvers (VII's) in the recent past a 5w-30 was a 5wt oil that was stiffened up with microscopic polymer coils that expand when heated making it act like a 30wt oil at operating temperature. IE the oils viscosity does not change as much with changes in temperature. They hold the oil molecules together kind of like rebar in concrete,

But VII's have shear problems, temporary shear where these coils align in tight spaces like a crank bearing and are less effective in holding the oil, there is also permanent shear where the polymers break and burn making a major part of sludge,

The cause of the Toyota “sludge monster” V6’s has supposedly be traced down to one high shear component in the valve train.

After a 5w-30 shears down you are left with straight 5 wt oil. Have you ever drained your oil and it came out noticeably thinner like water? That is shear. After shear I would rather be left with a 10wt than a 5 wt. a 5 wt is very thin at operating temperature and will allow more metal to metal contact.

This is one advantage of synthetics a more temperature stable oil molecule can be made requiring less VII's, this is also why weights with large spreads like 10w-40 got a bad wrap in the past.

Newer oils are supposedly getting better about this with more stable molecules and shear stable VII’s

 

[tarbe]

Raven

Assuming even Group 1 basestocks, how much more VII do you think the one has than the other?

The shearing issue is not as great a deal in any quality oil to account for a 50F operating range difference. We have both looked at quite a few analyses for 5W-30 and 10W-30 oils and it is rare to find one that shears below 9 cSt under normal operating conditions. And we know what kind of generally great wear numbers guys are getting using 20wt oils at 8 cSt. The additive packages today really negate a good bit of the viscosity fears that us older guys (talking me - don't know how old you are!) have/had. Heck, I used to run 20W-50 15 years ago cause I listened too intently to the Castrol commercials. Now I run 5W-30 year 'round in Houston. And with good analyses (I admit though to being a habitual oil changer )

That chart may have been written up in the 70's, but why would we want to use it today with oils containing moly and VII that is much more shear stable?

 

[tarbe]

The cause of the Toyota “sludge monster” V6’s has supposedly be traced down to one high shear component in the valve train.

I have one of these ('98 Sienna) so you can imagine I've read up on this.

There is debate among reasonable people as to the cause and extent of this problem. I personally think it is more due to the head temp vs block temp issue, combined with oil passage size issues. But I don't think there is a consensus even among the experts.

Either way, I can tell you that 2,000 mile oci with WalMart Supertech has kept my wife's Sienna purring like a kitten for 135,000 miles!

 

[cary]

I'll chime in here. I believe the worldwide oil chart is probably outdated. For any SL or SM oil produced today, you can use 5w-30 for the same temp range that 10w-30 is specified. As everyone knows, I am a proponent of M1 0w-40, mostly because the M1 30 weights are so light (near 20 weight) that they produce low oil pressure in hot temps which combined with the low RPM high torque nature of the LC motor can lead to higher wear than a heavy 30 or light 40 weight oil. For those of you that have cruised to bobistheoilguy.com, I fall in the camp that for most conditions an oil that is 12.5-14.5cst is optimal for most motors. This includes the mobil 40 weights and German Castrol. Basically, I like the lightest weight oil that you can get that has ACEA A3 approval.

I believe that Tarbe is correct that oil additive packages have improved a great deal. However, I prefer not to rely on the additive package to prevent metal to metal contact because the oil lacks film strength. Realistically, we could run 0w-20 and would only experience moderately increased wear numbers from a heavy 30 or light 40 weight oil.

As I have also said before, I believe that 15w-50 or 20w-50 is overkill for almost any use in a LC (and like Tarbe this is all I used for years having driven German cars for over a decade). The only time I could see a 50 weight benifiting a LC is one that has a supercharger or turbo, that is run in 100+f weather under heavy loads. Even in that case, I would expect overheating problems long before an oil related problem.

Finally, like Raven Tai, I am waiting for the elusive Mobil 1 10w-40 EP. I am at 8600 miles on this oil change interval. Just to mix things up a bit, I am going to use 5 quarts of 0w-40 and 3 quarts of Redline 10w-40 this change.

Cary

 

[wob]

Do you mean 5W-40 (T&SUV) or 15W-50?

Good eye.

It's 15W-50.

 

[alvarorb]

PCV Valve

A while back I made a comment to a friend that my rig was leaking engine oil from the mail seal behind the engine. He asked me when was the last time I had changed the PCV valve. I had never done so. He told me to change it and sure enough the oil leak went away. Apparently if the PCV valve is stuck with crud, gases find an easier way to escape... And that's through the mail seal.

Just my $0.02

Regards

Alvaro

 

[aamiggia]

What is the industry standard for acceptable oil consumption between oil changes? Assuming that there are no leaks.

My LX does not consume much oil, although I use 10W-30 and change it every 5-6,000 km.

My VW diesel on the other hand is going through oil at 1/2 liter per 1000 km. There are no leaks and no blue smoke (plenty of black smoke ) I've heard that this is relatively normal for older diesels.

 

[landtoy80]

Kurt, Where are you buying the Shell oil? It would be nice to stop the timing cover seep my rig has.

Walmart and Farm & Fleet.