The "W" on motor oil means winter not weight?!

So the old man comes in a little bit ago and asks me, "What does the "W" on the oil can stand for?".
I say "weight", of course, why?"

"THAT'S what I thought!", he says. He tells me a co worker's son came by after school and told them that they had watched a video on oil.
The boy asked his Dad the same question and the Dad gave the same response as me. Well, the kid googles it and shows them that it DOES stand for "winter".

WHAT?! I am certainly NOT the "sharpest tool in the shed" but, I distinctly remember (the old man and his co worker as well) all of my life saying 30 "weight"or 40 "weight" for the type of oil I needed.

I am sure I remember mechanics and such saying "weight" NOT "winter"!

I hope this isn't one of those parallel universe Berenstein/stain Bear things...

Just thought I'd share as I now feel dumb. Why didn't SOME mechanic along the way ever correct me? Were they just waiting for me to leave so they could laugh? LOL!

My Dad who was born in the 20's always said 30 "weight"!

SMH!

The numbers 0, 5, 10, 15 and 25 are suffixed with the letter W, designating they are "winter" (not "weight") or cold-start viscosity, at lower temperature.

Winter not Weight

i thought it meant Dubya ?

a reply to: TNMockingbird

Mechanics and everbody else says weight too... I have never heard this before..

Well, I have never seen a can with "S" on it.

So, all oil is made exclusively for Winter ?

Poppycock it means weight.

a reply to: TNMockingbird

Oil numbers do refer to what many call "weight" viscosity actually), but the "W" in the oil with viscosity ratings such as 5W30 means "winter." Essentially, it has a thinner viscosity in cold weather to compensate for the thickness caused by lower temperatures. This basically matters for cold starts; gets the lube flowing faster before the engine heat itself compensates for the cold temp.

How the science behind it works, I don't know, but essentially, both sides are correct in this one.

The numbers are indeed the "weight", and the modifying suffix "W" represents winter. I believe I have only seen the W as part of a multi-weight oil such as 5W-30 and never on a single weight oil.

Wow, learn something new everyday.
The w is for winter....who would have thought.

Makes sense.

but first i've heard of it.

a reply to: TNMockingbird

Ok so I have a mechanic background.

It's weight, it's meaning is how viscous or thin it is.

Lower number signify thinner oil...10w 30 is thicker than 10w 5.

So weight is simply how much oil is in solution, the conspiracy is why it's more expensive thinner.(this seems universal lol)

The poor guy was probably over simplifying because he is awkward with people.

Thinner oil offers less resistance on startup, so easier to start your engine in the cold months.

When it's hot however the machine needs to cool right or the oil will evaporate due to heat.

Synthetic produces less carbon build up when the overheating occurs, and it will occur.

Just a friendly hello



I give up on spell check


I re read the last replies.

Each oil is specific to how many cylinders the machine has, and how many strokes it does (RPM)

So some two stroke, dirt bike or fancy lawn tractors will take something completely different with other designations.

The lower the machine the less quality oil it needs to run.
Things like wiper snippers mix oil with gas so everything is lubed while it burns (nice RPM).

originally posted by: bigfatfurrytexan
Makes sense.

but first i've heard of it.

You don't need to, you lucky furball. Unless you're a TINO (Texan In Name Only) Seriously though, i wonder whether warmer places stick with the single weight, or if the multi weight is so common its just become the production standard and this cheaper than less common weights.

I know!
Thanks to all above who replied!

Treespeaker, I know...THAT'S the crazy part...LOL

From Popular Mechanics:

Viscosity (a fluid's resistance to flow) is rated at 0° F (represented by the number preceding the "W" [for Winter]) and at 212° F (represented by the second number in the viscosity designation). So 10W-30 oil has less viscosity when cold and hot than does 20W-50. Motor oil thins as it heats and thickens as it cools

Popular Mechanics

It's just weird...

From Shell:

The first number on a multigrade oil is normally followed by a W, which stands for winter. This number represents the lubricant’s viscosity under lower temperatures, giving an indication of how the oil will flow in the winter. The lower the first number, the thinner it is at low temperatures.

Shell.com

W for winter...???

I'm losing it and the OCD is kicking in...LOL!

5w-30

It's 30 weight oil, that has a 5w winter rating.


10w-30

It's a 30 weight oil that has a 10w winter rating, a test done at extreme cold temps.

a reply to: TNMockingbird

Ok so I guess I have been subject to my own dumbing down....sigh I an interest to push more understanding lol.

I relearned thank you for that.

Cheers

The W means weight as in oil viscosity. Thinner oil is for Winter.


a reply to: TNMockingbird

"W" is the nickname of my four year old son, did you know that? His brother gave him that name in his first year. So weird. Is this a coincidence? Because if not a coincidence, the brutality of it makes me think the parallel world acts as a mirror. It can be crazy cool if We ever get the hang of it. Time keeps us in a cycle though so it does get Cold in the Winter like it did last year. *shivers*

Cheers to coincidences because my heart believes that so.

P.S. Accept my apology if I have offended anyone or you don't understand my accent. Much love to you all. And "W" is singing himself to sleep right now. Music to my ears.

P.S.S I like to ramble.

I'll concur with the W standing for winter on oil labeling. A muti viscosity oil as in 5w30 will behave as a 30 weight at room temp, but behave like a 5 weight in cold temp, I don't remember the specific temperatures though.

Source: went to tech school for auto mechanics half a lifetime ago

And if anyone is interested I can lay down for you an interesting story on oil qualities among the top brands you're used to seeing and how your engine is affected, especially if you drive an older car. But it would be pretty lengthy, so I don't wanna type it on mobile if no one cares lol

originally posted by: FlyingFox
5w-30

It's 30 weight oil, that has a 5w winter rating.


10w-30

It's a 30 weight oil that has a 10w winter rating, a test done at extreme cold temps.

No, 5W-30 is a 5Winter rated oil that acts like a 30 when it's hot. It flows like a 5W when it's cold because the 5W is the base oil used when making a 5W-30 multigrade oil. Additives are used to improve the viscosity of a mutigrade oil at higher temperatures.

Up until the 1960s it was quite common to change the oil depending on the season and old handbooks from the period recommend oils as low as SAE 5W for very cold ambient conditions. SAE 30 and 40 grades would be typical for Summer use, and sometimes a SAE 50 grade would be substituted if the engine started to use more oil. Multi-grade oils were developed to allow year round use as a result of artificially raising the VI of the oil.

Scientists discovered the use of polymers and the fact that these would expand with heat. VI Improvers are polymer material that expands as the oil warms up. This does NOT thicken the oil as is often stated. It merely slows down the rate at which oil thins out as the temperature rises. The base oil in use in a multi-grade (aka multi-seasonal) is the first number (such as 10W or 20W), where as the second grade is the viscosity achieved using the VI Improver (such as 40 or 50). 20W50 is a base oil of SAE 20W and the viscosity grade at running temperature is SAE 50.

The Society of Automotive Engineers (SAE) developed a scale for both engine and transmission oils. The measurement is undertaken in a laboratory in accordance with standard procedures. W is Winter and oils with the W must meet the requirements of the Cold Cranking and Cold Pumping criteria.

www.kewengineering.co.uk...

There is tons of good info on the webpage and it all follows SAE standards that are followed over the entire world.