Oil weight and Oil Grade

Just for fun I am going to cut and paste some quotes from the main stream advertising media showing the terms weight and grade. Those numbers that the SAE (Society of Automotive Engineers) defines are actually grades such as SAE 30 but many sources call them "weights". The terms seem to be used pretty loosely. Standby.

Napa oil weight.PNG


SAE grades.PNG


Valvoline ad.PNG


Popular Mechanics oil weight.PNG


Napa II oil weight.PNG
 
Last edited:

Snagglefoot

Thread starter
Messages
7,019
Location
SE British Columbia, Canada
So there you have it folks. Grade is correct. Weight is a term that was used for many years and and is still kicked around, even by those who should know better. That takes a weight (I mean grade) off my shoulders. LOL
 
Messages
2,030
Location
Sequim, WA
Originally Posted by LotI
Boooo! Oils don't come in weights! show me higher density with higher grades and I will concede!
That's easy, just look at any product data sheet and you'll see increasing density with the higher grades. Here's an example: VR1 PDS Ed
 
Messages
1,421
Location
South Carolina
If you refer to oil viscosity by "weight", it's a dead giveaway of your knowledge on the subject. It's the same when people say "zinc" instead of ZDDP.
 
Messages
1,193
Location
PEARL River la
The problem comes from the "W". People always assumed it was 5 weight when cold then a 30 weight once hot. When I try to explain grades and temps people get confused.
 
Messages
4,112
Location
WA
Originally Posted by RDY4WAR
If you refer to oil viscosity by "weight", it's a dead giveaway of your knowledge on the subject. It's the same when people say "zinc" instead of ZDDP.
I wouldn't go that far..i find myself using "weight" or "zinc" on rare occasions despite being fairly knowledgeable abt lubricants. I know better but for some reason I do it...and it's not like this is my daytime job, so there's that. Sometimes old habits die hard......
 
Messages
4,112
Location
WA
Originally Posted by blupupher
I use the terms interchangeably, but primarily use the term weight when talking about an oils viscosity. there are other things to get more concerned over.
I've seen "weight" used on mfgs websites...so there's that. shrug
 
Messages
1,421
Location
South Carolina
Marketing is heavily invested in public perception even when that perception is wrong. They are simply using "weight" in response to public misconception that oil viscosity is "weight." That's it.
 
Messages
1,897
Location
Somewhere in time
Originally Posted by RDY4WAR
Marketing is heavily invested in public perception even when that perception is wrong. They are simply using "weight" in response to public misconception that oil viscosity is "weight." That's it.
C'mon man. You clearly stated that:
Originally Posted by RDY4WAR
If you refer to oil viscosity by "weight", it's a dead giveaway of your knowledge on the subject.
I then popped off 5 or 6 well respected industry players that use the terms 'weight' and 'grade' interchangeably. My examples ranged from an oil major to an OEM to trade groups to enthusiasts. We all know that the technically correct term is 'grade' because that's how the standard defines it. We all also know that many (most?) well respected professionals use the terms interchangeably in business environments and both are readily accepted. You're not establishing yourself as smarter than everybody else by making holier than thou statements about other people's knowledge base. Cheers!!! cheers
 
Last edited:
Messages
2,967
Location
Western S.C.
Most people and organizations who use the term "weight" as a synonym for "viscosity" or "viscosity grade" understand that that's exactly what they're doing. It doesn't mean they believe the substance in question literally weighs more or is more dense. That's a matter of one syllable being easier to pronounce than five.
 
Last edited:

MolaKule

Staff member
Messages
21,399
Location
Iowegia - USA
Originally Posted by JimPghPA
Unless you are in outer space where the effects of gravity are negligible, then we will call it mass, oh wait, that is weight, did I make the grade?
Ouch! LOL
 
Messages
24,594
Location
PNW
Originally Posted by Snagglefoot
So there you have it folks. Grade is correct.
"Viscosity Grade" ... to be more accurate. grin2
 
Top