Is 5W-30 in a 5W-20 engine O.K.?

[Audi Junkie]

Originally Posted By: Bryanccfshr
Originally Posted By: Audi Junkie
Where is the complete J300 specs, not just the corresponding temp / w-rating list.


http://www.sae.org/technical/standards/J300_200901

Just kidding the J300 Chart is pretty self explanatory

http://www.widman.biz/Seleccion/Viscosidad/SAE_J300/SAE_J300_English/sae_j300_english.html

As a matter of fact look up the PDS for each grade of oil and then go to WIDMAN's viscosity graphy plug in the temperatures and VI's etc..to determine the oils viscosity at your target starting temperature.


I mean the pumping limits for each grade, ie: 5w-20 vs 5w-40

 

[Bryanccfshr]

That is data that is not in the J300. You can find the data using the VI chart and charting the reference oils to the 5w rating limit of -35c.

 

[chevrofreak]

Originally Posted By: BuickGN
Originally Posted By: Bryanccfshr
BGN, that is an unfair and broad statement. Someof us thin oil guys spent our preteen years at a parts scrubber in a garage so they could learn from our mechanic relatives how this stuff was put together. Some of us bought our first car with the engine in pieces in a cardboard box in the back seat. Some of us filled that engine with Castrol GTX 20w50 because that is what grandpa used in the aircooled raceengines(1/4 mile dirt circles).
Some of us realize that technology has changed, AS much as Grandpa hated electronics, emissions and fuel injection do you not agree these things have improved automotive performance and longevity?
Same goes the 20 wt. Much talk about clearances but not much about the bearing diameters and journal width increasing the lubricated surface area and decreasing the point pressure that the lubricant must resist

I have no ego nor pride in my engine knowledge. I get paid to do something much different. I appreciate machines but I don't base my self image on them.


You're right, that last statement was to poke at certain individuals on here, not you or elk.


I hope it wasn't aimed at me, as I've been working on cars since I was young. I built a decently powerful smallblock chevy from the ground up when I was 15.

 

[BuickGN]

Originally Posted By: Bryanccfshr


Same goes the 20 wt. Much talk about clearances but not much about the bearing diameters and journal width increasing the lubricated surface area and decreasing the point pressure that the lubricant must resist



I meant to come back to this sooner. Bearing diameters and journal width is a valid argument, moreso than clearances. I've admitted that my car that requires a thick oil also makes a ton of low end torque and has a narrow bearing small journal crank. I would like to see some examples of a larger jorunal crank. I'm sure they exist but I'm not aware of any specific examples.

The other thing I wonder about is it would seem like the larger bearing would at least partially make up for the decrese in drag of the lighter oil, in other words it seems like you would nearly break even.

I would like to hear from some people that are more educated on journal bearings than myself.

 

[Bryanccfshr]

This is an interesting topic that hopefully we can find some facts on to discuss. I think as far as bearing friction it is all a wash. The primary parasitic loss from oil is from pumping it. the losses from viscous friction in the bearings would be difficult to quantify.

 

[OVERKILL]

Originally Posted By: Bryanccfshr
This is an interesting topic that hopefully we can find some facts on to discuss. I think as far as bearing friction it is all a wash. The primary parasitic loss from oil is from pumping it. the losses from viscous friction in the bearings would be difficult to quantify.


Yessir, which is why people randomly chucking HV pumps into engines because they think they are "helping" them are actually costing themselves power.

 

[BuickGN]

Originally Posted By: Bryanccfshr
This is an interesting topic that hopefully we can find some facts on to discuss. I think as far as bearing friction it is all a wash. The primary parasitic loss from oil is from pumping it. the losses from viscous friction in the bearings would be difficult to quantify.


Agreed. If we can find some of the type of engines mentioned, it would help validate the thin stuff to me. There's still the valvetrain and cylinders but bearings would be a good place to start. I honestly am not up to date enough on the newer stuff other than bearing clearances.

Someone like Doug would be really valuable right now.

 

[BuickGN]

Originally Posted By: OVERK1LL
Originally Posted By: Bryanccfshr
This is an interesting topic that hopefully we can find some facts on to discuss. I think as far as bearing friction it is all a wash. The primary parasitic loss from oil is from pumping it. the losses from viscous friction in the bearings would be difficult to quantify.


Yessir, which is why people randomly chucking HV pumps into engines because they think they are "helping" them are actually costing themselves power.


I'm guilty of that. At least the new engnie has a stock pump but that was only because the high pressure pump was scored. I remember going down the freeway on the pressure relief of 80psi for 4 hours straight. I think that was a poor choice lol.

 

[OVERKILL]

Originally Posted By: BuickGN
Originally Posted By: OVERK1LL
Originally Posted By: Bryanccfshr
This is an interesting topic that hopefully we can find some facts on to discuss. I think as far as bearing friction it is all a wash. The primary parasitic loss from oil is from pumping it. the losses from viscous friction in the bearings would be difficult to quantify.


Yessir, which is why people randomly chucking HV pumps into engines because they think they are "helping" them are actually costing themselves power.


I'm guilty of that. At least the new engnie has a stock pump but that was only because the high pressure pump was scored. I remember going down the freeway on the pressure relief of 80psi for 4 hours straight. I think that was a poor choice lol.


LMAO!

Yeah, the MOST guilty of this are the SBF guys.

An SBC being spun beyond stock RPM can actually benefit from the increase in oil volume.... We experienced this recently with a good friend of mine's engine in an S10.

An SBF? Not so much. The oiling system on the SBF is much better than the SBC, and the stock pump is more than adequate for the vast majority of applications, even being turned well beyond the stock RPM range.

An HV pump in a 302 does nothing more than rob HP, and requires the use of a hardened drive shaft because the HV pumps will actually licorice-stick the stock one.

 

[Propflux01]

Originally Posted By: Bryanccfshr


No!!! J300, learn it.

 

[Bryanccfshr]

I apologize for my blunt manner, it was hot yesterday and I was short.. The J300 will tell you that 5w means a that at -35c the oil will be no thicker than 60000c that is the cold weather pumpability. at 32f the differences between the 5w30 and 5w20 can be noticable.

 

[zoomie]

My first oil change was at 3500 kms, a typical example of mileage for an all highway trip mileage (Hinton, AB to Kamloops BC) is 40mpg. After the oil was changed and 5W-30 was used a typical highway trip (Moses Lake, WA to Sandpoint, ID w/much warmer ambient air temps) 39mpg. I dont have cruise control but may install one soon. My car is now at 10K kms and will get 5W-20 at its next oil change, and Im curious to see what a repeat of the first trip will get in terms of mileage with a better run-in engine with cruise.

 

[Audi Junkie]

it's not like you're running 15w-40 in there.