Now break-in oil is another complex issue that a lot of people do not understand, myself included (!).
There is break-in of engine, crankshaft, other parts, and there is break-in, seating of rings.
For the first, an oil rich in molybdenum, assembly grease, as found in a new engine is supposedly desirable,
...but for ring seating a non-detergent oil, and low in molybdenum other friction improvers is supposedly the best, or at least that is what some knowledgable people say.
So accordingly, to that theory, the best approach is to run the engine for a very short period of time with very light load, say 20 minutes, 30 miles or so, then to dump the molybdenum rich factory break-in oil, and put new non-detergent oil for part two of break-in, i.e. ring seating.
Ring seating is best accomplished with some load (see various methods of break-in, for ring seating).
After such, which can be accomplished within
20-50 miles depending on aggresivenes, the oil should be changed yet again. This time to normal conentional, or synthetic, whatever is to be used.
That is what I have heard is this true? I would like to break in my Forester properly so any input is greatly appreciated.
If you were to read my text with with a better effort at undestanding you would have joked writing "bar chain lube" ...as this thing is the stikiest oil around, second only to Valvoline VR1straight 60 mixed STP.
That was true in bygone days - and if you rebuild an engine. The factory engine is pre-broken in. The engine is run up on natural gas and run for a few minutes or powered by an electric motor (depending on the manufacturer/assembly line) to check oilpressures etc - which gets the cam broken it - and the machine finish on the cyls etc is so exact that basically breakin is pre-done.
All you need to do is jump in and drive it like you stole it, and change the oil at the recommended first interval. Varied speed and load for the first 500 miles never hurts - don't get it too hot - and that's about it.
That is where you are wrong. - at least as far as the 0 or 5 base. A 0W30 or a 5W30 will both run off at the same rate in a warm engine.
Nope. They will all basically have the same amount of oil left on the moving parts. At least as far as the 0 , 5, 10, and 20 pase number are concerned. The W40 and W50 oils MAY leave a bit more behind.
HOWEVER - when you let that engine sit until cold, and then start it- the 0W and 5W based oild will pump IMMEDIATELY into the moving parts, while a 20W, and even a 10W, will take a number of seconds, and possibly hundreds of revolutions of the engine before the oil reaches the moving parts under pressure. You get worse cold-start wear with the thick oil than with the thinner oil. It has been proven time and time again.
The only point where I dissagree with the automotive companies' recommendations is in using low ultimate viscosity oils - like 0 or 5 or even 10W 20 or 30 oils instead of 5w40 or 0W50 oils. They do that strictly for CAFE ratings - not engine life. With today's synthetic engine oil technology the wider the viscosity range the better. Flow easily when cold, protect with adequate viscosity when hot.
Like I said before, even 0W oil is thicker when cold than w50 is when it is hot. Multigrade oil does NOT thicken as it heats up, or thin when it cools.
You would have a true cold start after 2 hours in Winterpeg. I stopped my Dart in Winnipeg Manitoba in January 1972 for less tha 6 hours with 20W40 oil in it, and it would not crank over in the morning. There was lots of oil in the bearings and oil galleries - but it was still a "cold start". After 3 hours under the heaters in a garage, the engine turned over and started - and blew the oil filter gasket right out, after having bulged the filter can to the splitting point - in less than 5 seconds of running. The lubricating qualities of that non-circulating oil were not as good as a 5 weight oil would have been.
You use whatever oil you want in your car. You pay the repairs when they are required. Believe what you want - but please don't pass it off as "knowledge" to those who don't knopw.
You are not an automotive engineer - or even a professional mechanic. I'm not an automotive engineer either - but I AM a professional mechanic. I am also relatively knowledgeable about aircraft engines and the requirements of lubricating oils in that application (high powered air cooled engines)
And what do you base your self-esteemed opinion on, may I ask?
Mine is grounded in solid empirical observation, yours is probably empty talk, parroting mantras that circulate the internet.
When I moved to USA, I was a young student and didn't know better and bought a brand new GM car that turned out to suffer from bad piston slap at startup, that was particularly severe in the summer. Phoenix and Las Vegas summer. I experimented with various oils, 10w-40 Castrol GTX was what I used and it slapped forever. Annoyed, and desperate, but not being financially able to dump my the bad investment, I tried to alleviate the problem by changing oil type.
20w50 Castrol GTX did not help much. In 90F ambient temps, the car would slap on cold start in 2 hours. I tried Castrol 30wt, much improvement- cylinder walls would remain covered with a thick enough layer of oil for around 6-8 hours in 90f temps, but not long enough to get rid of a a bad cold-start every morning.
Finally swicthed to 40 wt VR1 Valvoline and it adhered to parts long enough that I would not get piston slap for longer that 12 hours, actually it would not slap for about 24 hours in hottest weather.
I kept the car for more than 20 years, always using 40wt Valvoline VR1 oil in summer, and a mix of 15w-50 Mobile1 and 1 quater 50wt Valvoline in colder weather (winters in Reno 40s 50s F). The 2,8L V6 GM pushrod engine had 225k miles when I sold it. Didn't consume a single drop of oil, althoug I was usuing 4-6 oz of Marvel Mystery oil in gas, and some of it has a tendency to go past rings and make it into oil, but nonetheless never needed to top oil between changes. I've seen the car on the road recently, close to 6 years after I sold it, and in good shape.
This is my experience to back my wors, Sir.
Yours is likely just empty talk, sprinkled with your personal crap. I asked you not to bring this up- I have no way of judging what kind of mechanic you are, or were, ...might have been a good one, might have been a bum. In a market economy, and particularly American , where there are enourmous financial flows from abroad, and people live on credit from abroad, there was room even for a bum mechanic to survive.
It is obvious that thin oil flows better at cold start, I never argued that. My problem in oil selection is to choose an oil that would flow fast when cold, and not drip off of parts to fast when hot or cooling so there is some healthy layer left protecting parts at next startup.
It is really very simple.
...and drip off of parts so fast that piston slap at startup on a brand new Subaru is called normal. I too believe CAFE is to be blamed, that is why I asked here about what to put in a new Forester.
I think I will start with 5-30 for a short period of time, first
1000 miles. Then go to some mix with weight 7.5w-35, or 7.5-40 for summer. This is what I seem comfortable with, but must emopirically verify once I get the car.
I am worried about the upper bound as I here people say that these engines have tigher tolerances, etc., and that bearing will be starved with a 40, or 50 upper bound oil.
You seem to like 0-50. I don't like the 0 part, but am all ears on the 50, ...maybe 40, the Fb engines have VVT which is supposedly sensitive. You said 50 could be OK if 0-50. Isn't it going to be too thick at operating temp?
OK, but once it gets hot, arent those bearing supposed to get thin stuff when hot?
I get your point. There is something as too thick, and I have made that clear in my first post, if you care to read.
Likewise yourself, just because you write you are a mechanic means absolutely nothing, you might be a bad one, very bad one, there are a lot of bums out there.
I earned my Cllass A automotive mechanic's licence back in Dec 1971 and I've worked on just about anything you can think of other than a Trabant. Moskovich to Rolls Royce, Lawn mowers to large industrial and construction machines, and I've taught both high school and trade school auto mechanics.
That's what warranty is for - GM would have put a new engine for you if you presented your case properly. Ford replaced one for me for the same problem.
That's a crock. Piston slap is not a lubrication problem, and throwing a sleeping bag over to quiet it down is NOT a fix - YOU are no mechanic - that is obvious
That is a crock. An engine with "piston slap" when started that responds to heavier oil didn't have piston slap to start with. More likely poor or maladjusted hydraulic lifters. You never did say what engine was in it.
Talk to any of my 1000 or more past customers, or any of my former students - and you will get a totally different story - or any of my friends who still value my input and my troubleshooting skills
Extremely simple. The closer you can get to a 0W50 oil,, the closer you are getting to "your" ideal - but you will never figure that out
You don't get it. You are an absolutely clueless guy when it coms to auto mechanics and lubrication. I won't call you a "bum mechanic" or an idiot or anything derogatory like that - but you do NOT know anything. That is as obvious as your nationality - which has nothing to do with it.
Check the clearance specifications and compare them to older engines. Very little difference - and you still can't get it through your thick skull that hot 50 is still thinner than cold 10 - or even cold 0.
Like I said - hot 50 is thinner than cold 5
They still get thin stuff when it's hot. Hot 50 is very thin Hot 20 is like kerosene. The ONLY reason for a 20 weight when hot is fuel economy.
I have lived long enough in Germanic countries including Anglosaxon, to know that Polish natonality has worst associations here, and that is why you try to bring it, mention it. Are you Germanic Sir?
The public education system in this former British colony US is virtually disfunctional, and most people live pretty isolated, almost nobody speaks a foreign language (!) with any degree fluency, ...so people learn about others and outside world mostly from Hollywood movies, war propaganda, other sorts of paid propaganda, all sorts of misinformation, ...a very sad state of affairs not only for Polish people, but ultimatelly the saddest for Americans themselves, as there is eventually a bill to be paid for lack of information and stupidity.
thank you, anyway, you've helped me understand where you are coming from mister,
thank you,
Now that you have properly introduced yourself, one question of merit, you keep repeating, and insulting me, regarding my alleged lack of understanding about hot 50 oil being thinner than 0 or 10 cold.
I understand that perfectly, believe me, but I hear that engines are built around a certain oil weight at operating temperature (!)
So if a particular engine, its torelances, passages, bearing clearances are built to a specs for a 30 wt oil at operating temp, say 5w-30, then a thicker 0w-50 weight may not be appropriate, as it will be much thicker at operting temp, than a 30 weight.
...is this not going to cause oil starvation, inadequate oiling, at operating temps, at least not be optimal...given or assuming normal driving, not racing, towing, other hot running situations where oil thins further?
Any thoughts, perhaps from someone willing not to insult me verbally, or through assumption, at their first thought?
I am not an american, and some of my good neighbours are Polish. And I'm not German either.
You were trying to insult me. I said I would not insult you.
Check the clearance specs on your new Soob, and on a 20 year old engine with the same crankshaft/main-bearing sizes, and the same engine bore - and tell me how much difference there is. Then take into account the surface finish in today's engines - and if the spec is the same the old engine actually had smaller oil clearances some places because of the poor surface finish..
You will find the chance of oil starvation due to engine clearances using the same oil as was recommended 20 years ago in today's engine is pretty slim. And you could not BUY a 0 or 5W rated oil - which reduces the chance of dry cold starts significantly.
Back in the day I ran 10W40 in the winter and 20W50 in the summer on all my cars - but if 0W50, or even 5W40 synthetic had been available then, I would have used it. I do now.
Both my vehicles specify 0w20 to 5W30 oils - which I do not like - even in quality synthetic. I'm running 5W50.
Temperature range here runs from -25 to +30C -
On my airplane engine - a converted air cooled 6 cyl american automotive engine, I'll be running 15W40 all-fleet- but it never starts or runs in the cold - and it IS an air-cooled engine.
If I had acsses to such information I would not be asking questions in the internet.
Naturally,
Slim. See we are missing this cruxial piece of info to make an informed decision about upper bound numbers. You say its likely that clearances, specs are the same, or only slightly tighter. I myself believe the same. But there is this issue of an upside down oil filter draining, which you contest, buy people report otherwise, and v v t, varuiable valve timing, that supposedly is sensitive to oil thickness.
More questions that answers, for sure, and Subaru is not saying much just "0w-20 synthetic required" without any further explanation.
This is very disrespectful to their clients in my opinion. In this age of never ending cornucopia (and public debt I may add) more and more large companies are becoming increasingly arrogant- can afford to treat their customers like cattle as sales skyrocket.
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