What's the diff between 0W-30 and 5W-30?

[Jeff]

Admittedly this may be nothing more than a teapot tempest nevertheless, Mobil1 makes both products and says 0W can safely replace 5W. I did a search and couldn't find anyone asking this question.

OK brainiacs, why wouldn't I use the 0W if it is just as good as 5W? In SoCal low temps aren't a concern but if 0W circulates a tad faster at startup, is there some compelling reason not to use it?

On my first engine (really long story and I'm still PO'd at Ford) I used 0W and the insides were very clean. In bulk at Wally Mart, 5W is about $18/5 qt container and the savings would just about pay for the filter. The downside is that I need to buy a separate qt to top off the engine between changes.

What are the real world reasons (data por favor) to use one over the other? Is that extra split second of circulation only going to give me an extra little bit of increased engine life? Any mileage bonuses using one instead of the other?

Thanks in advance!

 

[S.Matsushige]

I think you maybe right in assuming a tad faster circulation through the engine. I would also think perhap better mpg and increase engine life as well. I'm no scientist, but easier flow could also mean less drag in the engine. Maybe someone else could shine more light on the subject. Good question though.

 

[aldive]

Does anyone have any data or just seat of the britches feel for any increase in MPG using the 0 w 30 vs 5 w 30. I know I picked up 1 MPG going from 10 w 30 to 5 w 30.

I am always looking for better mileage.

Thoughts?

 

[leenjen]

i use 0W-30 in my daytona turbo. i didnt notice any difference when i switched from 5W-30. but i use it just because i figure a slightly better flowing oil is always better. i've never had any problems using it and a turbocharger is really rough on the oil, so that says something.

 

[AgExplorer]

There's really not much difference. The 0W will flow a little quicker on start up because it is designed to flow at a lower temperature. At operating temperature, they will both protect like a 30 weight oil. Fuel mileage will depend on the vehicle itself and the brand of oil used. A lot of people have reported increased mileage when using Mobil 1 or AMSOIL. Of course, these are both synthetics and have the ability to lower operating temps and friction.

As far as hard data, you'll have to go to the manufacturers' websites and check out their technical service documents. Some will be easier to figure out than others but most will have much of the same data from standardized SAE tests.