Cold Start Up Projection: Am I fooling myself?

[lovcom]

I live in a fairly moderate part of the country: Southern California. Our winters are 35F to 50F at night, and of course our summers are 85F to 100F but mostly mid 90s.

Having said all that, I just did an OCI and put in M1 0W-20, because my rationale is that I want low viscosity oil in during start ups, even if the garage is never less then 40F during the winter. My thinking is that I want very thin oil flowing fast during start up.

My 2007 Yaris is spec'd for 5W-20.

So am I just kidding myself, or is there some safe logic to my rationale? From reading on this forum for several weeks now, I harmonized my thinking and drew some conclusions. Still, I'm far from being an expert, so if you think my thinking is flawed, please do let me know.

 

[Silber Igel]

Ahhh, at last!!!!! A guy who thinks like I do!! I'm looking for fast flow and easy pumping until the oil gets to operating temp and its rated viscosity. For all the 'right' reasons!!

 

[lovcom]

Ok, but is the science there to prove our ways? lol

 

[mechtech2]

If you can afford '0' weights, go for it.

 

[lovcom]

Quote:

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If you can afford '0' weights, go for it.

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Well, its an extra few bucks for the 4 quarts my car needs...I suppose anyone could afford a few extra bucks, yea?

I'm not really worried about saving $$...I just don't want to fry my engine with "too thin" an oil ;-)

 

[jmb106]

Have you read Dr.AeHass papers on motor oil? Your rationale is correct. The fasts flow at start up is what you want and as thin as posibble at operating temp, 10psi per 1000rpm is the goal. I switched my 00 silverado & my 99 civic from 5w30 to 5w20 about a month ago they run much smoother, rev easier, and get better mpg. You are on the path to oil harmony

joe

 

[Panzerman]

If you trade it every four years, by the time it wears out, someone else will own it.

 

[Steve S]

yep.

 

[Pablo]

Your logic is fine. In a modern engine you should always use the lowest viscosity oil which gives you the 100°+ viscosity you need! IOW if the oil has the film strength necessary for hydrodynamic protection (and the necessary AW and EP additives for extreme contact), then you don't need a thicker oil for "more protection". This applies at all temperatures.

The added benefit is less work required to move the oil around, if said oil is a lower viscosity at start temperature.

The exceptions start in extreme pressure points (flat tappets) in older style engines, in turbos, etc.

 

[JohnBrowning]

You are not going to see any difference by going thinner in your ambient temp. range!!! I would say your kidding yourself. Now with that said I doubt that you will notice much of a difference onw way or the other. I am sure your yaris's engine will sound quiter with M1 0W40 or RTS 5W40 in it then 0W20 but until you do some UOA it's hard to say anything definative. We do not have a lot or any Yaris UOA that I recall on this site so takeit for what it is.

 

[jazztrumpet216]

35F is a cold start up?! That's downright balmy for Wisconsin in January!

Seriously, you don't need the 0w oils. If they make you feel warm and tingly, great. But you have very little to worry about. You could probably be running 10w oils and be fine. If that Yaris is still in warranty, I'd just stick to the 5w-20 and call it a day.

 

[TurboTravis]

(reality)You could run any off the shelf 5W-20 in that car, and as long as you change it at the proper intervals the engine in that car will outlast everything else(/reality).

T

 

[Titan]

I'm thoroughly amazed at the responses above. As the OP asked, using LOGIC and RATIOINALE, Pablo has the correct answer. Many of the remainder of the answers are based upon conjecture...and from people with a lot of "experience" on the board, at least, a lot of posts on the board.

The scientific evidence supports Pablo's answer, Dr. AEHaas' writing delivers the science in layman's terms fairly clearly.

 

[lovcom]

From what Dr. AeHASS and Pablo and others have said, using the thinnist oil can protect morning start ups, even if the "cold" ambiant temperature is just a balmy 35F - 40F. It seems that flow is a bit more important then pressure, from what I gather in several other threads on this site.

From Dr. AeHASS' writings, it seems that even 0W is too think for the start up phase, so I figure using 0W-20 will give my engine a bit more protection during start ups, and once the engine is at normal operating temperature, the 20 part of 0W-20 will protect at that point, even as the Fall/Winter hottest part of the day is in the low to mid 60's. Thanks everyone for their chiming in.

 

[lovcom]

furthermore, since most of engine wear happens during start ups and the time the engine is getting to optimum operational temperature, it is this time of operation that I am trying to protect. Once the engine is at operating temp, I trust 0W-20 to protect is the hotter temps....although I doubt I'll use 0W-20 during summer months as it can hover around around high 90s low 100s in my area. I welcome more responses, so please don't hesitate.

 

[Steelhead]

what proof do you have that the M1 0w20 has lower viscosity and better oil pump flow at 40d F than the 5w20 it came with?

what proof do you have that the M1 0w20 has less wear and bearing protection at 220d F plus oil temps than the 5w20 the car came with?

 

[lovcom]

Quote:

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what proof do you have that the M1 0w20 has lower viscosity and better oil pump flow at 40d F than the 5w20 it came with?

what proof do you have that the M1 0w20 has less wear and bearing protection at 220d F plus oil temps than the 5w20 the car came with?

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I don't have any proof. If I did, I wouldn't be asking about this issue in this thread, now would I?

If can you offer any proof or valid arguments against my using 0W-20 one way or the other, that would be very helpful.

Thanks.

 

[Curious Kid]

I agree with what's being said about using the lightest viscosity oil with required additives....but that ideal can have a broad range the more one varies in driving style/operating behaviors - say 6 miles @ 30mph average to and from work m-f, and then 50-60 miles towing 1500lbs at 40mph average in the hills. Throw in ease of lubricant availability and filter supplies, etc. Somewhere a compromise must be had, though perhaps one adds a thermally regulated oil cooler and preheater whose thermal surplus comes from the engine coolant (I think Gary A. was working on such a system), though there's more to present issue and added flow restriction, blah blah blah.

No matter, using the lightest visc. over the OCI for the expected work load still sounds logical for start-up film development and fuel economy (especially for short distance drivers). That said, those doing 1 yr OCI's and with greatly varied degrees of operation duties, might find them selves with less thin options - did I say that already?

Thinner oils at operating temps. might also leave one desiring increased filtration levels to further ensure component longevity by filtering out the debris that would otherwise not posed a bridging concern with thicker oil films under similar operating conditions.

Truth be told though, there's only so much one can do and plan for before simply operation becomes too much of a hassle!

Take care.

 

[Curious Kid]

Oh yeah, and as far as start-up wear...there's part fit - thermal expansion/saturation that is thought to account for a good deal of it at least in the piston-in-cylinder, related fuel and combustion gas blow-by, thermal activated additives in the oil, etc.

Mind you I'm speaking as an "outsider" here, working with some information gleamed from readings here, the "www" and publications.

Take care.

 

[jazztrumpet216]

Quote:

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I'm thoroughly amazed at the responses above. As the OP asked, using LOGIC and RATIOINALE, Pablo has the correct answer. Many of the remainder of the answers are based upon conjecture...and from people with a lot of "experience" on the board, at least, a lot of posts on the board.

The scientific evidence supports Pablo's answer, Dr. AEHaas' writing delivers the science in layman's terms fairly clearly.

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The OP also asked if he was kidding himself. While I don't disagree with the scientific reasoning, I have taken quite a few engines to high mileages in Wisconsin winters, and none of them ever saw anything remotely as thin as a 0w-20. The closest any of them have ever seen to that is a 5w30, and that includes the Voyager in my sig that has run from 5w30 to 10w30 to even 10w-40. Most people will tell you that a 10w oil is perfectly safe down to 0F. Is thinner better? Yes. But IMO, you're splitting hairs at 40F. If we were talking -40F, I would be in 100% agreement with you.