Which Engine Oil?

[qwank]

I think I'm going to just run Mobil1 5w30 in mine.

[powerhaulic]

i didn't like the sounds coming from my engine on cold start from 0-20.

Since changing to 5-30, its nice and quiet in the morning

[Cowpie]

Was reading the posts on page 3 of this thread that gave quotes from GM. What became very clear early on is that GM has no idea of the dynamics of viscosity, at the least the guys who write the manuals.

 

A 0w20 and 5w20 have the very same viscosity, ball park 8.6 cST at 100c (read: Operating Temperature). The only difference is the cold flow rating, and it is not all that dramatic of a difference. And the difference only becomes a consideration at some very seriously low ambient temperatures at engine startup. It does take significantly more polymeric viscosity improvers to meet the spread of a 0w20 than it does to meet a 5w20. And those VI's are the part of a motor oil that can shear under pressure and break down.

 

So if it were mine, I would opt for the 5w20 since it tends to be more shear stable and has lower burn off rate that will leave fewer deposits, especially important in regards to AFM and DI engines. And yes, there are 5w20 oils that are dexos1 approved, a lot of them, if that is a worry by some. Per the EPA, whatever oil the OEM uses to get past the emissions and fuel economy testing is what they must require of the vehicle owners. 0w20 is what they use for the testing, to their advantage with the test procedure, hence what they "require" in the manual.

 

But even using a 5w30 probably is not an issue. These same engines, outside the U.S., the OEM's recommend higher viscosities depending on the location.

[MIDNITEZ71]

i have read many threads over the years on the debate about which motor oils to use.just like many of us that love your Chevy trucks.we could go jaw to jaw with the ford/dodge guys on which trucks are the best.the same thing could be said on what brand motor oils we use.

before buying my first chevy truck just a few months ago.my first chevy was and still is a 1969 SS 396 chevy chevelle hardtop.i have owned this car for over 30 years and have been reading threads on chevelle/muscle cars forums for decades.the debate is always the same with little or no proof to which name brand of oil is truly better then the other.in the muscle car/classic car world the debate started on which brand would protect their motors from Flat tap cam lobe failure.a lot of hotrod guys started to experience cam lobe failures on newly built high performance motor with only a few hundred to a few thousand miles.some blamed poorly manufactured cams while others blamed newly formulated motor oils.at some point in time oil manufactures removed some types of additives that where harmful to a cars/trucks catalytic converts.but by removing these additives muscle car guys started to have more and more flat tap cam lobe failures.with that debate switched to which brands of oils had more Zinc to help protect their motors from these failures.like i said before the debate was always the same with no real proof to which brand was better.

then along came 540RAT on the forum Teamchevelle.540RAT is a Engineer by trade and muscle car/hot rod enthusiast.after reading threads like this one on which brand is better and seeing first hand flat tap cam lobe failures.540RAT started to send out samples of motor oils and have them tested to find out their true Quilty.after years of testing all types of oils,he compiled a list of his top ranking oils and started a blog listing all his Data.here is a quote from his blog as he tells you a little about who he is.

Before we get into motor oil tech, let’s briefly touch on a little background info. That way people will better understand who I am and where I’m coming from. Here are my credentials:

Mechanical Engineer

U.S. Patent Holder (Mechanical device designed for Military Jet Aircraft)

Member SAE (Society of Automotive Engineers)

Member ASME (American Society of Mechanical Engineers)

Lifelong Gear Head, Mechanic, Hotrodder, Drag Racer, and Engine Builder

I’m a working Professional Degreed Mechanical Engineer, and Mechanical Design Engineering is what I do for a living. A Mechanical Engineer is clearly the most qualified Engineer to test motor oil that was formulated by Chemical Engineers, for wear protection capability between mechanical components under load. But, as you will see below, the following write-up is not intended to be a chapter out of an Engineering textbook. And the intended audience is not other Engineers. There are no formulas, equations, charts or graphs. The intended audience includes Automotive Enthusiasts, Gear Heads, Hotrodders, Racers and Engine builders. So, it is written in normal everyday spoken language, rather than overly technical jargon. That way, it will be the easiest to follow and understand by the widest possible audience. And some key points will be “intentionally” reiterated from time to time as the information presented here progresses, to emphasize those points.

here another quote

June 20, 2013

MOTOR OIL ENGINEERING TEST DATA

The date June 20, 2013 just above, is the date this Blog was first started, NOT the date of the information included. It is regularly updated with the latest information, as indicated by the date several paragraphs below.

NOTE: The motor oil wear protection test data included in this Blog is from performance testing of many different motor oils, which shows how they compare relative to each other. The focus is on the motor oils themselves. Therefore, the resulting comparison data applies to ANY engine that uses the oils included here, no matter if the engine is used for racing, daily driving, grocery getting, watercraft, or any other activity.

********************

here is another quote

I’m a total perfectionist when it comes to technical issues. And those who know me personally, know that I would never jeopardize my reputation or my integrity, by posting test data that would turn the Hobby/Industry on its ear, unless I was absolutely sure about the data I put out there. Of course I’ve always known my carefully generated data is completely accurate. And to make that clear to the world, you will see below that my test data EXACTLY matches real world severe over-heating experience, real world race track experience, real world flat tappet break-in experience, and real world High Performance street experience.

...............................

now 540RAT has taken his own time and money to sample OVER 190 different motor oils..........he has tested pretty much every name brand and type of oil you can think of.how many of you on this forum or any other forum can say that even test at least one motor and had it compared to the next leading brand?i know i can't and i bet neither can you......his Blog lays out all the Data in black in white and the numbers speak for themselves.i must warn you this is a VERY VERY long read but try to take the time and educate yourself on the oils we use.we spend a lot of money on these vehicles new/old,our weekend fun runner or our daily drivers.the first part of this blog is about oils for High performance race/street engines, his later work relates to MODERN ENGINES and their oils.after reading the debate should be put to rest but then again we know that will never happen.taken this info and pick which oil suits your needs and pass this info onto others to help educate them.

once again very long read so enjoy......here is the link

https://540ratblog.wordpress.com