Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance 2.5L running 5W-20.

Originally posted by ajdulina:

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5W-20 has no more or less protection than 5W-30. The last number only deals with viscosity at LOWER temperatures. High revs have nothing to do with it. However, a cold engine has more HP with 5W-20 because the crank can sling it around easier.

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I suggest you read up a bit.

The first number is the oils weight at 0 degrees

The second number is the oils weight at operating temperature (210 degres)

The small the number the thinner (less protection, but better flowability) the oil has.

Also the stock oil pump has no problem flowing all the oil (5W30) out of the pan as is at high rpms.

My advice is to skip the thinner oil and stick with a true full synthetic like Mobil 1.

Not that it's true being both oils share the same weight when cold (5), but why would it matter if the engine had more HP when it's cold. You NEVER race an engine or put it under heavy load when it is not properly warmed up. That's a quick and sure fire way to shorten the life of your engine!

I know what i'm talkin about.
I would suggest you real aliitle too.
The number have nothing to do with oil weight. Those numbers are the SAE standard for oils viscostiy. 0W-30 is darn near water and has little to no protection during startup. You are correct that the first number is for 0degF and the second is for operating temp(212F). I would suggest going back to the 5w catagory while your connecting rods still have a journal. Your operating temp is still the SAE 30 rating and you have nothing to gain by putting in a 0W oil. I meant to say that you get more HP all around rather than a cold engine. The lower SAE 20 rating allows the oil to be thinner without sacrificing viscosity during startup. It allows the oil to breakdown at a lower temp but my engine doesn't get that high anyway.

What would you all say to a 5W-50 synthetic? I put it into a high millage car before with no regrets and wanted to do the same for the 2.5 now.

For 1 - I run Mobil 1 5W30 (previously recommend by myself)

For 2 - less viscosity = less protection & you yourself stated a 20 oil has less viscosity (I.E. thinner) than a 30 oil. Which is exactly the point of my post.

Your original post said a 5W20 oil and a 5W30 oil are indentical at operating temps. I.E. "the last number only deals with visocity at "LOWER" temperature - high REV's have nothing to do with it."
Which is incorrect! You even corrected yourself in your last post by stating the second number IS at higher temps (operating temp - 210d)
Also high rev's are where you encounter the worst thermal breakdown, cylinder pressures, plain old high speed moving parts (high revolutions!) and where an oil's viscosity is key to preventing damage and high wear!

So I definitely stand by my original post. What do you stand by?

Also; again... What oil filter do you use?

Well, then if 0W30 is thinner, then it would offer better protection @ startup just for that reason, because it can circulate through the engine quicker, at least this is my understanding of it, which came from quite a good source. I'm open to an explanation of exactly why it would be worse at startup, and thus would happily go back to 5W30. Anyone want to explain this one to me?

IMHO there is little difference in normal operating temp between 0W30 and 5W30 Mobil 1.

The big deal is the modifiers used to get the larger difference in viscosity.

I have run 0W30 Mobil 1 in contours before. I would also consider a 5W20 Mobil 1 or 0W20 Mobil 1 for the winter. Where I live that would be too thin for the summer time.

For the track I would run a straight 30 weight oil like Redline or MAYBE a 10W30.

I wouldn't run any 50 weight oil in a duratec. I have this argument with my father in law all the time.

He has a SBC in a pickup that he runs 20W50 in. The engine has 150K miles on it, leaks like a holy bucket and runs like crap.

He had to rebuild his Stratus' engine due to oil related failure... why? he put 20W50 in it in October and didn't change it until April... startups were hell on that poor car.

My Maxima has 273K miles on it and runs 5W30 just fine it doesn't leak any oil and runs perfectly fine.

My contour has whatever the dealer put in it (I purchased it used and will be putting Mobil1 5W30 in it within the next 2 weeks.

Just for clairifcation

First number = cold viscosity
Second number = hot viscosity

The big problem is when the numbers are too far apart in dino oils... 0W30 and 5W20 oils should be just fine for a duratec that isn't on a racetrack.

Originally posted by ajdulina:

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I've seen 5W-20 in almost all parts stores now. Its not a synthetic blend(unless thats what you want, its availible). ITs availible from most oil manufacturers. The Duratec was designed to run a light oil, and i think this change was due to cold start wear. I used to get alot of cam noise starting up every morning for about 4-5 sec. until the oil got up there, i think the thinner oil should cut that time down to just a sec or two.

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Motorcraft claims their oil is a synthetic blend. It says so predominately on the bottle. I don't know if other oil companies also make that claim (I doubt it).

I know this seems to go against the prevailing religion in this group but I would not expect to keep a 7000 RPM street motor together and healthy for the long run by using a 5-30 oil, synthetic or conventional. I have been a strong proponent of using Mobil 1 0-40 oil in todays high performance engines (just as Porche, BMW & MB currently do). Before you guys tell me how �??thick�?� it is, take a look at a few sources of information.
http://www.epa.gov/otaq/cert/dearmfr/ccd0112.pdf
The above is an interesting government publication showing the �??guidance�?� the feds give the auto and oil industries which mandates 5-20 wt. Oil. The same �??guidance�?� was issued some years ago concerning 5-30. This is not a suggestion from an automotive engineer concerned with engine life, it is a directive from a Federal agency concerned with forcing us to get one tenth of one MPG better fuel consumption at the expense of engine life.
Spend some time on the Euro and Australian web sites of the auto and oil companies and see what you find when they can talk without worring about EPA guidlines.
The Euro Castrol site has an oil selector page. It specifies 10-40 or 15-40 for the Mondeo.
There are several instances of referring to 10-40 as a �??lighter weight�?� viscosity here.
Mobil Australia has the same type of oil selector guide on their site. Even though there is a footnote indicating Ford reccommends 5-30, Mobil then specifies 0-40 as the oil to use in the Mondeo.
You all might consider an upgrade from 5-30 oil if you participate in �??spirited�?� motoring with your Contours.

And for all you guys that are unsure of the difference between SAE grades and how much difference there really is between the various multi weights, request temp-viscosity graphs from one of the oil manufacturers tech groups and check out the actual cP figures for real world temps between 20 deg F and 230 deg F. Like they say - a picture is worth........

Thing is I can't find 0W40 anywhere... so 5W30 or 0W30 are pretty much the next best thing..

Mark I agree with you to some extent.

Also the proper "European" oil is 5W40.

The only problem I see arise with that is when I asked Mobil about which of their synthetic oils contained viscosity index improvers (not good for high rpms) and mainly gearing it towards their 0W30, 5W30, & 5W40 selection.
All they sent back was that their 5W30 did not use any?
Now they didn't say the 5W40 did, but they said the 0W30 did. Maybe whoever answered my question just didn't know about the 5W40 since they omitted the answer, but it put enough doubt in my mind to not switch to it for the summer.

Also I do routine oil analysis of my oil (Mobil 1 5W30) and the SUS viscosity (@210d), even after ~4k miles/4 months, is well above the average for a synthetic and miles above any conventional oil & the contaminents are well below either. This shows my filtering (K&N for both air & oil) & the oil's anti-wear characteristics are great.
So I am not too worried about it breaking down & if it can withstand my constant abuse it surely can take anyone elses...