5W to 0W brings pumpability difference?

[Kira]

VEHICLE: 2005 Ford Ranger 4.0l SOHC @ 56,700 mi. 5W-30 and strict OCIs by the PO and me.
NOTE: Ranger freaks recommend pre-cranking the engine using the "clear flooded engine" method to pump oil up.
Turn the key to ON, floor the accelerator and crank the engine to pump oil. It's good for an occasionally run engine.
It took 8 seconds of cranking to make the oil light go out. 5 was enough to ensure a quiet start-up.
It's good for the rest of the day thereafter.

I just changed the oil using 0W-30 synthetic oil.
This morning 10 seconds of cranking failed to extinguish the light.
The engine started completely quietly after said cranking.

I'm not concerned nor asking advice. I just think the 0W-30 requiring so much more time is noteworthy.

 

[dogememe]

Lol all you’re doing is burning out the starter prematurely.

 

[Kira]

Possibly
However, there's a very brief "chirp" when I start it dry.
I've settled on 4-5 seconds of cranking/priming at the top of the day. This gives me a strong, 'silent' start-up.
I do not crank the engine until the oil light goes out.

 

[kevperro]

It is a 2005 Ford Ranger. I'd stop changing the oil and hope that it dies a sudden death.

 

[Wrenchturner44]

It is a 2005 Ford Ranger. I'd stop changing the oil and hope that it dies a sudden death.

NOT! Especially since it only as 56k miles. I might consider going back to the 5w oil though at the next change.

 

[nascarnation]

It is a 2005 Ford Ranger. I'd stop changing the oil and hope that it dies a sudden death.

That's harsh, man. I'm a GM guy but those old smaller trucks are great.

 

[kschachn]

Pumpability is really a go/no-go proposition. Either it pumps or it does not.

In terms of viscosity, that is highly dependent on temperature. Unless you were performing this test at -25 or below, the viscosity difference in a 30-grade between a 5W and a 0W winter rating is likely negligible, more or less.

 

[labfan]

Owned a 2000 Ford ranger and used anything from 30 to 50 and it was a timing chain failure that killed it. Burned no oil at almost 400k. Never did any silly things like that. Bump to a 40 grade euro and just use it normally. Sleep easy.

 

[fonecord2]

Owned a 2000 Ford ranger and used anything from 30 to 50 and it was a timing chain failure that killed it. Burned no oil at almost 400k. Never did any silly things like that. Bump to a 40 grade euro and just use it normally. Sleep easy.

What is the advantage of the euro oil?

 

[labfan]

What is the advantage of the euro oil?

Costs the same but better chain protection and you can go for longer drains while still preserving good pumpability. Quaker state euro 5w-40 at Walmart is what I'd use. Same price as the regular 5w-30. No reason to not use it instead.

 

[Rand]

If 0w or 5w makes a difference in priming at normal temp.. there is something else going on. maybe it lost prime.

Because? -- Physics.

 

[DGXR]

Maybe the 0w is too thin to build enough pressure at cranking RPMs? But the 5w builds enough pressure at cranking RPMs to trigger the pressure switch? Just a thought.

 

[kschachn]

Maybe the 0w is too thin to build enough pressure at cranking RPMs? But the 5w builds enough pressure at cranking RPMs to trigger the pressure switch? Just a thought.

At any sort of normal ambient temperature the viscosity of those two winter ratings of the same grade oil is going to be close if not identical. In fact it’s possible the one with the 0W rating may be thicker.

Only below about -30 is the 0W guaranteed to be thinner.

 

[Rand]

Maybe the 0w is too thin to build enough pressure at cranking RPMs? But the 5w builds enough pressure at cranking RPMs to trigger the pressure switch? Just a thought.

not how it works. the first number is the winter rating. the second number is the viscosity range.
as mentioned the 0w30 might even be thicker than the 5w30 at normal temps ie above 0f.


they would be extremely similar oils as not "one is water and the other honey".

In any event they are similar enough to have the same viscosity.. there would be a bigger viscosity difference if one was stored in your house and the other the garage.
So something else is going on.

 

[DGXR]

Yes. 5w30 is 5 at 0*c and 30 at 100*c, more or less. At ambient "cold" temps, the 0w is supposed to be slightly thinner than 5w. Very slightly. Maybe slightly enough that the oil pressure switch needs just that bit more pressure provided by the 5w to trigger. That was my thought. Here's my next thought: if the 0w may actually be thicker than the 5w, and 0w30 / 5w30 are "similar enough to have the same viscosity" then apparently the winter ratings are nonsense lol.

 

[kschachn]

Yes. 5w30 is 5 at 0*c and 30 at 100*c, more or less. At ambient "cold" temps, the 0w is supposed to be slightly thinner than 5w. Very slightly. Maybe slightly enough that the oil pressure switch needs just that bit more pressure provided by the 5w to trigger. That was my thought. Here's my next thought: if the 0w may actually be thicker than the 5w, and 0w30 / 5w30 are "similar enough to have the same viscosity" then apparently the winter ratings are nonsense lol.

What? That makes no sense.

 

[Rand]

Yes. 5w30 is 5 at 0*c and 30 at 100*c, more or less. At ambient "cold" temps, the 0w is supposed to be slightly thinner than 5w. Very slightly. Maybe slightly enough that the oil pressure switch needs just that bit more pressure provided by the 5w to trigger. That was my thought. Here's my next thought: if the 0w may actually be thicker than the 5w, and 0w30 / 5w30 are "similar enough to have the same viscosity" then apparently the winter ratings are nonsense lol.

uh no. the 5w and 0w is a winter rating. not viscosity.
IIRC
the 0w is tested to be under a certain viscosity at -40C and the 5w is tested to be under a certain viscosity at -35C

What you said is a common misunderstanding.