Just how badly do we need 0wXX and 5wXX?

[Vaca]

I know this is obvious but may be worth remembering in the context of this thread.....

....xW-30's at virtually ALL starting temps (from minus XX to 80F) are still thicker than a straight 30 at full operating temps....

 

[G-MAN]

Originally Posted By: Vaca
I know this is obvious but may be worth remembering in the context of this thread.....

....xW-30's at virtually ALL starting temps (from minus XX to 80F) are still thicker than a straight 30 at full operating temps....


This goes without saying. The kind of cavitation issues mentioned in the post above only occur at extremely low temps. A modern SM rated SAE 30 can be safely used, IMO, down to 20F.

 

[Merkava_4]

Quote:
A modern SM rated SAE 30 can be safely used, IMO, down to 20F.


That's the information I was waiting for; Thank You sir!

 

[bob_ninja]

Originally Posted By: G-MAN
...
I guess my point is that modern 0wXX and 5wXX oils were and are the product of a quest for reduced operating friction and the resultant improvement in fuel economy. From a mechanical failure standpoint, absent near arctic conditions, modern engines will do fine, IMO, on straight SAE 20 or SAE 30 year round.


Can you please link the study that compared modern engines using single vs 0Wxx/5Wxx oils during North American winters showing similar wear? What were the findings? thanks

Originally Posted By: G-MAN
NB: I went to the grocery store last night around 11 pm. My Chrysler 300M has Valvoline SAE 30 in it and had been sitting all day. The temp was 33F and it started right up like it always does with no unusual noises or protests. (In fact, as I have posted before, startups with SAE 30 are actually quieter since I don't get any bearing rattle on the initial startup rev.)

Just some food for thought...


How does the "sound" relate to engine wear? How did it start at -10F? -20F? Show us the wear numbers before (using 0Wxx/5Wxx) and now (using stright).

thanks

P.S.: So far I see no data to backup you claim.

 

[e36'n]

Last night I went to start my car after it was sitting outside in -17C (1.4F) and it had a tough time starting. I have Rotella 10w30 CJ4 in it with a top up liter of Chevron Delo 15w40. I've never used non syn oils in it before and it's never had a problem starting in the winter.

I'd be inclined to say that in cold weather environments like Edmonton, the base stock matters more than the "weight". I've used GC 0w30, M1 0w40 and 15w50 and all have never had cold start issues in any of my cars.

 

[bob_ninja]

Originally Posted By: G-MAN
Originally Posted By: Vaca
I know this is obvious but may be worth remembering in the context of this thread.....

....xW-30's at virtually ALL starting temps (from minus XX to 80F) are still thicker than a straight 30 at full operating temps....


This goes without saying. The kind of cavitation issues mentioned in the post above only occur at extremely low temps. A modern SM rated SAE 30 can be safely used, IMO, down to 20F.


But what is this opinion based on? An opinion is formed based on more than "sounded fine the other morning"! Maybe engines do last longer these days BECAUSE nobody uses straight 20 and 30 any more!!! If you are proposing cancelling multi-weight oil advance in oil tek you need some compelling data/arguments/experiences.

 

[meep]

You have to remember, also, cars didn't just fire up back in the 50's. You needed healthy start-rpms to build up enuf compression. No fuel injection, only carbs with a manual or "auto" choke. You had to grind to get the mixture flowing. Battery capacity was quite limited....our 283 V8 came with...what, 350-400 CCA and a 28Amp generator that needed 1500 engine rpm to keep the headlamps lit? In my experience with older cars, it was a race to start the car, and keep it running, before you depleted the battery. Even at +20F, oil vis mattered at startup.

M

 

[G-MAN]

Originally Posted By: bob_ninja
Originally Posted By: G-MAN
Originally Posted By: Vaca
I know this is obvious but may be worth remembering in the context of this thread.....

....xW-30's at virtually ALL starting temps (from minus XX to 80F) are still thicker than a straight 30 at full operating temps....


This goes without saying. The kind of cavitation issues mentioned in the post above only occur at extremely low temps. A modern SM rated SAE 30 can be safely used, IMO, down to 20F.


But what is this opinion based on? An opinion is formed based on more than "sounded fine the other morning"! Maybe engines do last longer these days BECAUSE nobody uses straight 20 and 30 any more!!! If you are proposing cancelling multi-weight oil advance in oil tek you need some compelling data/arguments/experiences.


It's based on looking at the vis of a typical SAE 30 down to 20F and comparing it to a typical 20w50 or 15w40 at that temp, noting that most oil makers specifically state NOT to use 20w50 below 20F or 15w40 below 15F.

 

[Iain]

Originally Posted By: Bluestream
G-MAN, you are right on with your first post. Multi-grades were developed so people could use one oil year round. (an oil with training wheels) It was a compromise, but worked for most people who had no clue about oil. Also, when a vehicle left the factory they did not know what time of year, or what part of the continent it would end up selling. One oil year round met that need. (BTW Pontiac did make an OHC engine in the 60'S)

You people in the south who think 32F is cold, don't know cold. I have seen -40F three times in my life. Starting is more dependant on battery condition, and state of engine tune than oil. We had -40 for four days on a snowmobile trip to Quebec in the 90's, and my high mileage Dodge van with a carbureted six started every morning (on 10W30) Some guys from the US had a Chev Suburban that started up, but the tranny was frozen and wouldn’t shift. They jacked up the rear axel and let it idle in Drive for four hours before it thawed out. It you have never been in those type of temps; it's like going to another planet.

In my Explorer I should use a 30 weight for Summer, but I keep getting sucked in by the $1.00 a liter 10W30 specials...

Even though I live in a more moderate climate now and probably don't use my current fill to the full extent, I will say that I lived in Winnipeg, MB during a winter several years ago. It routinely went to -35C from December - February.

That experience taught me it's best to be prepared for the worst possible conditions, just in case you should actually need it.

 

[Saab9-3]

If cold weather visc is such an issue with sae30 and a person wants to stick with an sae30. why not just plug the block heater in all the time so the Oil is a little warmer at start up? Is there a problem with using the block heater or an oil pan heater all the time when the weather gets colder

 

[bob_ninja]

The title refers to 0Wxx and 5Wxx, not 20W50 and 15W40. You should have said, "Just how badly do we need 20W50 and 15W40?"

The limits generally specify when performance becomes unacceptable. If the specified limit is 20F then you'd want to stay well above it, lest considerable damage occurs. That means your temps would have to be no less than say 30F. Then to account for unusually cold mornings, your average low temp would have to be even higher, say 40F. How much of US has average winter temps low of 40F????

 

[G-MAN]

Originally Posted By: bob_ninja
The title refers to 0Wxx and 5Wxx, not 20W50 and 15W40. You should have said, "Just how badly do we need 20W50 and 15W40?"

The limits generally specify when performance becomes unacceptable. If the specified limit is 20F then you'd want to stay well above it, lest considerable damage occurs. That means your temps would have to be no less than say 30F. Then to account for unusually cold mornings, your average low temp would have to be even higher, say 40F. How much of US has average winter temps low of 40F????

 

[PT1]

Originally Posted By: bruce381
The push for multi gradea came about NOT for fuel mileage improvment but for over head cam motors that would eat the cam when using straight grade oils up north in minus temps also back then the oils were all GPI at best and cold flow was a problem.
bruce


This is true. Even with the pusrod engines at GM. Way too much top end damage warranty $$ shelled out on the Corvette. That is how the Mobil1 endorsement came about. I personally know this for a fact.

 

[G-MAN]

Originally Posted By: PT1
Originally Posted By: bruce381
The push for multi gradea came about NOT for fuel mileage improvment but for over head cam motors that would eat the cam when using straight grade oils up north in minus temps also back then the oils were all GPI at best and cold flow was a problem.
bruce


This is true. Even with the pusrod engines at GM. Way too much top end damage warranty $$ shelled out on the Corvette. That is how the Mobil1 endorsement came about. I personally know this for a fact.


The official word from GM at the time Mobil 1 became factory fill in the Vette was that it was being used in the new LT1 engine (which had reverse flow cooling) to obviate the need for an external oil cooler.

 

[Tree Hugger]

Originally Posted By: bob_ninja
The title refers to 0Wxx and 5Wxx, not 20W50 and 15W40. You should have said, "Just how badly do we need 20W50 and 15W40?"

The limits generally specify when performance becomes unacceptable. If the specified limit is 20F then you'd want to stay well above it, lest considerable damage occurs. That means your temps would have to be no less than say 30F. Then to account for unusually cold mornings, your average low temp would have to be even higher, say 40F. How much of US has average winter temps low of 40F????

No. You can't reasonable make a SWAG at a safe margin for unusally cold mornings (30F instead of 20F) and then double that safe margin 'to allow for unusually cold mornings'.
I think the 30F is a little large of an allowance, but not silly. 40F is just silly.

 

[wolfc70]

Yes the cavitation occurs in cold temps. With 30 wt oil, cold is approaching 30F. I just poured some Citgo SAE 30 (SM) in to a cup, It is very thick, even compared to regular Citgo 5-30, and the Amsoil XL 5-30 is water compared to the Citgo 5-30, currently it is 34F outside. How long does it take for oil to reach the cams on your 3.5l V6? The thick oil remaining in the lash adjusters prevents any noise from being made. I would really like to see a UOA on 30wt oil in temps below 35F, just to see what is being worn. Oil flow is just as important as oil pressure, especially during start up. I'm not trying to pick a fight or say that you are wrong, I too wonder what point single weight oils become detrimental, The manual for my Briggs Vanguard (riding mower) states that SAE 30 is safe down to 45F, below that 5-30 is recomended.

 

[BarkerMan]

You have to consider that the oil that hung around in the valve train does some lubrication while waiting for new oil flow to arrive. The idea that your engine running 30w oil at 32F will destroy itself at startup has to be wrong. There has got to be increased wear in such a case but I think that the amount of wear is a bit overblown.

 

[Towel_Rail]

Originally Posted By: Saab9-3
If cold weather visc is such an issue with sae30 and a person wants to stick with an sae30. why not just plug the block heater in all the time so the Oil is a little warmer at start up? Is there a problem with using the block heater or an oil pan heater all the time when the weather gets colder


I can think of one -- where do you plug in the block heater when you park your car at work? Or at the grocery store?

 

[JohnBrowning]

OHC engines do not eat cam's with thick oil. A properly designed head will have pockets under each lobe of the cam's that stay's filled with oil so that when you start the engine the cam lobe's get dipped in this oil so they are not dry before they make contact etc.... Everytime I have swapped out cam's on an OHC engine the cam bearing cap's always have a large amount of oil on them to keep the cam's floated.When I worked for GM the word from the Orlee(?) the oil CZAR at GM was that the main problem from useing thicker then recomended oil's was with spun bearings dureing cold start's dureing winter.That is why GM went to almost all 5W30 across the board!!

 

[Bluestream]

Originally Posted By: [RT
ProjUltraZ]
Originally Posted By: Bluestream
I have seen -40F three times in my life. If you have never been in those type of temps; it's like going to another planet.


omg that's worse than stalingrad


Perhaps, but the women were better looking!