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      03-18-2019, 11:56 AM   #79
warpeacelove
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Quote:
Originally Posted by Supahone View Post
So what are your thoughts on using 0w40 euro blend synthetic oil?
Way to thin of an oil. No protection.

Use 15w-40.


Think of a 10W-40 oil as meaning that the oil is similar in flow to a 10 weight based oil, but when it's hot, it will have the "viscosity" protection of 40 weight oil. It does NOT turn into 40 weight oil like so many people think multi viscosity oils do. They are called "multi viscosity" for a reason, not "multi weight" oil. It isn't meat gravy! It doesn't get thicker when it heats up. Don't believe me? That's an easy one to prove. Check your dip stick when your engine is cold. The oil stays on the dip stick as normal because it is at it's normal, thicker cold "weight". Now check it when the engine is hot, the oil will run off that dip stick like it was thinner than water! Like I said, it ain't gravy and it does not thicken when it gets hot.

20w-50 oil is the same way. Think of it as having the cold flow of a 20 weight oil, and the protection, or "viscosity", of 50 weight oil when it gets to running temperature. This is because the molecules in the oil are kind of like tiny little springs. When they heat-up, they expand, and when they are cold, they contract... in simple terms. This expansion and contraction does not thicken the oil when it gets hot. It still thins-out like any oil does. It just means that a 20w-50 oil will be a little thicker when cold than something like a 10w-30 or a 10w-40 oil would be. This means a 10w-30 or a 10w-40 oil will get to the places it needs to go quicker than a 20w-50 or a straight 30 wt oil will because thinner oil is easier to push and it can get into the tighter clearance places easier than a thicker oil can. It's easier to drink a soda pop through a straw than it is a milkshake. It's kind of along those same lines.

Now, what's a good weight to run in your engine? Most modern car engines have very tight clearances and need thinner oils so the oil can get where it needs to go to do it's job as fast as possible. Thick oil has a hard time getting in tight places or getting where it needs to go until it warms-up and thins out. That's why we always warm-up our performance engines before we started driving or putting any loads on the engine. This makes sure the oil is warmed-up, thinned-down, and has had time to get where it needs to go to start protecting the internals of the engine before loads or RPM is given to it.

Thinner oils have less drag on the oil pump and drive gears, which equates to less parasitic power loss. But again, too thin of oil can also mean less protection under high loads and high heat, so there is no one perfect answer. The problem with thin oil is that most oil and advertising is geared towards the East coast where it is very cold in the Winter so thinner oil is more suited. The West coast almost never gets that cold, so the oils we use out here need to be thicker with higher viscosity numbers. I would never recommend 0w-30 or 5W-30 oil in ANY "American" performance engine, let alone any normal street cars in warm weather. That stuff is like water and can't take the kind of heat and loads of an American performance engine. Import engines use tighter clearances and have different designs than older "muscle car era" American engines have, so when it comes to oil, we aren't talking apples to apples, it's more like apples to oranges. This can go on and on, so I'll try to keep it brief. If you look in a Valvoline catalog under oil recommendations, they recommend 30Wt. in trucks that drive in weather over 80 degrees. Well, that is pretty normal weather for the West coast.

The nitty gritty of oils: Mineral oil is refined, and the refining process is pretty good, but not perfect. Here's how my friend from Redwood Oil explained it to me so it was easy to understand: Crude oil has everything in it, from gasoline to diesel to all of the weights of oil, and each part is processed out of the whole crude oil. Once the oil has been refined out of the crude, also known as "heavies", what they do to get the different weights is by separating the different sizes of molecules that make-up the thickness of the oil.
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