Real World difference between a 0W and 5W oil

[demarpaint]

Originally Posted By: ionbeam22
For winter service I would want to be using the 0W oil, and would probably add some MMO to enhance cold cranking.


That is how I dealt with the winters for many years, especially when I planned a winter time trop to the Adirondacks. You'd be surprised how much better an engine started treated with MMO in the oil. I mentioned this before. My cousin and I both ran Mobil 1 5W30.

On a -25*F day we both started our cars side by side, you be amazed how much easier my van with the MMO had started up. His Toyota moaned, groaned and sounded like it had a pound of marbels in the engine. The year before I had Mobil 1 5w30 and on a similar cold morning I thought my van was giving birth w/o the MMO added.

 

[SteveSRT8]

hmmmm, and what exactly is the viscosity of MMO?

But I agree it helps in cold weather. Our relatives in deepest Ohio use it in the winter in their 4 wheelers.

But the OP has had his question answered ad infinitum.

Get thee to a store and buy some high end 0w-something and drive!

 

[demarpaint]

MMO is a 5 grade oil by itself IIRC. Back in the day I was referring to 0W oils didn't exist, and even with a 0W oil it still helps in extreme cold.

 

[ionbeam22]

Originally Posted By: SteveSRT8
hmmmm, and what exactly is the viscosity of MMO?


Not sure, but it is pretty thin, and per turtle wax has a pour point of -65*F. It's not just a matter of pour point though, since the ability to disrupt gel formation is the key thing.

 

[aquariuscsm]

I`ve wondered how diferent say,Mobil 1 0W40 is compared to Valvoline 10W40 (which I`m using now).

 

[Audi Junkie]

Some time using Widman's visc calc is quite informative.

http://www.widman.biz/Seleccion/Viscosidad/Conversiones/Graph/graph.html

People are surprised that some 5w oil can be thinner than 0w. Some 10w can be thinner than 5w.

I suggest too doing a freezer test with 5w-40, it does not do well compared to 10w30.

In fact, 10w30 is a good choice in all seasons and in many applications.

 

[JohnBrowning]

Not much! Some 0W oils do use better base stocks then their 5W counterparts but not always. So if it is just a different VII package and everything else is the same not much difference. That is the problem though you can not make a blanket statement like that based on the first digit of an oil. Each company does their own thing their is nothing like a Universal truth. This is why we have to run them and look at them and get VOA's etc..... Too often people come here looking for a simple answere but just like life oils are seldom simple!

Take Mobil 1 0W40 it works great in almost any application that a 5W20 or 5W30 works well in. In applications calling for a true 40Wt. it fails to turn in decent number's normaly. What could I possably take from that observation and turn into a blanket statement? Nothing!Like wise not all 0W30's are greated the same. GC 0W30 is almost a 40Wt. and holds it viscosity and HTHS very well in fact after about 1500 miles in real world use GC 0W30 is thicker then Mobil 1 0W40! that is also why it performs so well! You see the point I am getting at. If you want to see if a 0W will do anything for you application pony up ran some and do a used oil analysis other wise you will never have a clue if it is going to be a step in the right direction for you. OW fluids normaly make the bigest difference in applications that seldom reach operating temp like short trips. Once the oil is up to temp and the thermodynamic effieceny has been reached in the cylinders their is no longer any improvment in the milage return.

 

[21Rouge]

Originally Posted By: JohnBrowning
Some 0W oils do use better base stocks then their 5W counterparts but not always.


This was always my gut feeling i.e I'll go for the 0W30 over the synthetic 5W30 as am getting a better quality oil in the 0W but I know now that one can make a 0W30 from GRP III base stocks. Of course this is probably not true for boutique 0W or of course GC.

 

[dsmith41]

Another newb question: Rotella, or any 5w-xx HDEO for that matter, is marketed as a cold weather oil. Does this come down to the difference between a gasoline engine and a diesel engine? Such as, 5w-xx is considered thin for a diesel engine but just average for a gasoline engine? Why do diesel engines need a heavier oil in the first place?

I really think I am going to switch to the Rotella 5w-40 here soon just to experiment and see how it will do. I honestly do not think it will do any lasting serious damage to my engine for just one OCI. I'll monitor fuel economy and have a used oil analysis done at the end to see for sure. I'll be sure to post my results.

 

[ionbeam22]

Originally Posted By: Audi Junkie

I suggest too doing a freezer test with 5w-40, it does not do well compared to 10w30.


The key thing is the higher number since the viscosity of a mixture is ultimately limited by the most viscous thing in it.

5W-40 is going to be different than a 10W30 due to it being thicker on the top end.

Net result is to match the top end and then go as low as you can on the bottom end E.g if your engine calls for 10W30, you can safely use 5W30 and 0W30. Using the lighter weight oils will improve cold cranking and reduce viscous friction inside the engine.