endobong

I cant find 0w-30 Castrol Syntec German anywhere

GreasyB

Sounds like she knows more then some of the guys here

caldercay

Don't get hung up on it - it's not that important (the rumor is that it is
PAO based versus Group 3). Like I said, don't worry about it.

caldercay

Never, EVER, under-estimate a woman when it comes to technical prowess

CheshireCat

I feel like I'm beating a dead horse here, as this topic has been beaten to death... But it's clear that you don't understand.

In a multi viscosity rated oil, Say a 5w30.

The first number is a description of oil's flow properties at 0*C

So at 0*C a 5w30 oil flows like a 5.

The second number describes how the oil will flow at 100*C

So at 100*C a 5w30 oil will flow like a 30.

If I was comparing a 5w50 to a 5w 30, both would flow similarly at 0*C but the 5w50 would flow slower and with more resistance at 100*C

You can get charts for the cst (thickness)ratings of various oils throughout their temperature ranges over at bobistheoilguy.com

dangalla

see that is where your wrong, it clearly states that it will not thin more than a 30wt would, not that it will flow like a 30wt.

like i said earlier this is extremely difficult to understand properly and even harder for me to try to explain it. i wish i never posted in this thread, i should have known better....

CheshireCat

Sir, I'm not trying to be right or wrong, just trying to explain.

At 0*C a 5w30 oil is thinner than a 30 at )*C

As these oils warm up, both are getting thinner.

By the time both oils have reached 100*C both oils will be about the same thickness.

Thus "it will not thin more than a 30wt would" In fact, because the 5w30 started thinner, it will have thinned less. But at 100*C they will be about the same thickness.

Injuneer

You really need to back off, because you obviously do not understand what some of the knowledgable people are telling you. Cheshire Cat has explained it EXACTLY, technically correct. At cold temperatures, e.g. a "5W" oil at 0*F may have a higher kinematic viscosity than "30" oil at 100*C (212*F). As noted correctly above, the oils are not "thinner" or "thicker".

In the simplest possible terms.... maybe this approach will make it easier for you to understand:

If you try and start the engine with a straight 30-weight oil, it will be too viscous to circulate, and the engine may be damaged due to lack of lubrication. So.... to start your engine cold, you drain the 30-weight oil, and replace it with straight 5-weight oil. That oil does have a lower visocity than 30-weight oil when it is cold, so it circulates more quickly, and prevents engine damage.

But now you have a problem... as the engine heats up to normal operating temperature, and the oil approaches 100*C (212*F), a 5-weight oil would have a very low viscosity, and could not support the bearing loads. So now you have to drain the 5-weight oil, and replace it with 30-weight oil, which has the correct viscosity at 100*C to support the bearing loads.

Since it would be a bit inconvenient to switch the oil as the engine warms up, multi-viscosity oils were developed. These oils act like a 5-weight oil at 0*F, and act like a 30-weight oil at 100*C. The viscosity characteristics of the oil change as the oil temperature changes.

A 5W-30 and a 10W-30 oil will (nominally) have the same viscosity at 100*C. But the 5W-30 oil will flow better when the engine is at 0*C. Recognize, however, that there is a range of allowable kinematic viscosities for a "30" (or any other weight) oil, and it is possible that one brand of 5W-30 oill may not have the exact same viscosity as another brand 5W-30 oil.

Here's a decent info page from Amsoil (not endorsing them, just using their "layman" explanation).

http://www.upmpg.com/tech_articles/motoroil_viscosity/

dangalla

i am sorry i posted in this thread to begin with

BTC

Actually, a 5W-50 would display the characteristics of a 5W oil at 0 degrees and the characteristics of a 50W oil at 100 degrees.

sbs

But, as everone in the thread has tried to explain to you, it is exactly that, if you are using the definitions of those terms provided by the SAE.

But, nobody talked about "thin" and "thick" until you used them to set up a straw man argument that exists only in your mind.

Nobody in this thread has made the claim that any particular oil at 100* is thicker than any particular oil at 0*, which is why your posts appear to be completely clueless to the rest of us.

Injuneer

What part of this do you not understand. How many people have to explain to you that a multi-viscosity oil acts like the "5W" rating when its cold, and acts like a 50 oil when its hot.
You're the only one who thought that the oil got "thicker" when it heated up.

BUBBA

When you have absolutely nothing else to talk about----bring up the subject of oil. BTW not unusual for a full-out race car to use 50 wt oil.

BUBBA

And....I just know that the person who said that using a straight 30W is asking for trouble must not be very old, since that is all that most people used to use before multi-viscosity oils became the norm.

Turbozombie

So....no issues with running a 5w-50? Oil pump should be ok with this?