0W40 Can Ruin A 5W20/5W30 Oil Spec'd Engine?

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The engine in my 07 F150 is spec'd 5W20. In 1997, its 1st year in production, it was spec'd 5W30. In 2000 Ford spec'd 5W20, and back spec'd 5W20. I have used whatever weight oil I wanted to and it is still running with over 150K miles.
I have been doing a lot of reading about 0W40 in engines such as mine. There are mixed opinions about it and how it can ruin my engine. Some are even stating that using a 0W40 in a 0W20 spec'd engine will ruin it as well. Some are positive responses. Such as, use it over any other oil. It will protect your engine, esp. at start up and operating temperature.
What gives? I have had PP EURO 0W40 in my engine for almost a month, maybe more, and it has NEVER run as quiet as it does now. Am I reading opinions from "ARMCHAIR QUARTERBACKS" or people that actually know what they're talking about?
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I just put PP 5W30 in my 2010 Ford Ranger 2.3, never been quieter. I use PP 5W30 in my 16' Challenger R/T Hemi 6 speed, quiet as a church mouse. Going to use PP 5W30 in my 17' Jeep 3.6 next oil change. I'm done with 5W20.
 
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You need to answer some simple questions.

1. What is the operational temperature of the oil in your engine?

2. What is the viscosity of the 5W-20 oil at that temperature?
If we trust the people that designed the engine, then we can assume that this viscosity is somewhere in the range of viscosities that will give the engine the best protection. We don’t know how narrow or how wide is this range.

3. What is the viscosity of the 0W-40 oil at that temperature?

4. Does this new viscosity is inside that range?

To put you an example. Assume that your engine operates at 100°C and that the viscosity of the 0W-40 oil at 100°C is the same as the 5W-20 oil at 80°C. in that case using the 0W-40 oil is the same as operating your engine permanently at 80°C. Do you think this could ruin your engine or not?

Obviously you will need to calculate the real numbers to get a definitive answer.
 
I've gone a step further and put 15W40, SAE40 and 20W50 in several xW20 engines. See my last few "post your last oil change" posts. Today 10w40 in a 2013 Matrix. 70K miles on it now, been on thick oil since new, just one example.
Last fall 0w40 went in an 07 Highlander hybrid. Before that my mother's Windstar vans, a few Taurus wagons, Chrysler Intrepid, cammed American V-8s etc.
 
Originally Posted By: BlueOvalFitter
Am I reading opinions from "ARMCHAIR QUARTERBACKS" or people that actually know what they're talking about?
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Where you been reading this stuff?
 
If 0w-40 is somehow going to make an engine speced for a 0w-20 or a 5w-20 in your climate fail, they'd be in real trouble up here with a 0w-20 when winter hits. Historically, automakers have specified a range of viscosities for different ambients. The armchair guys are the ones falling for the trap in the manual that 0w-20 must be used under all conditions lest the sky fall.
 
No idea what they're talking about.

I'm running German (now Belgian) Castrol Edge 0W-40 in my 5W-30 spec'd GM LL8 for over 65,000 miles and 6 years without a single issue. Heck GM's export spec calls for ACEA A3! My 4.6L 2V equipped Expedition supposedly spec'd for 5W-20 runs Motul 8100 X-Cess 5W-40, as does my Grand Marquis with a modified 4.6L 2V that sees WOT very regularly. My LY7 equipped Cadillac, spec'd for 5W-30 also runs Motul 8100 X-Cess 5W-40, as does the Mitsu which recommends viscosity based on ambient temperature. The Cologne SOHC equipped Explorer, also spec'd for 5W-30, runs Castrol Edge 0W-40. I could care less about CAFE or fuel economy.
 
On the contrary, I experience better fuel economy with thicker oils. Within reason of course. I'm beginning to think that a VII containing engine oil of the same grade, may provide better fuel economy than an engine oil without.

We know how temporary shear works in the bearing space with RPM rise, but how do VII's act on cylinder walls under stress?

Does the engine oil thin from shear and reduce friction?
 
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mid stroke is high shear as well.

Honda have started increasing main bearing size and reducing clearances, actions that increase drag/friction, but increase MOFT...they are doing that while still reducing viscosity, apparently in an effort to balance that off against piston assembly friction.

(OTR concepts use thermal barrier coatings mid stroke on the coolant side to drop the local viscosity - that's where I think passenger cars will ultimately go)

edit...devcon block filler sounds like a plan.
 
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Originally Posted By: Falcon_LS
I'm running German (now Belgian) Castrol Edge 0W-40 in my 5W-30 spec'd GM LL8 for over 65,000 miles and 6 years without a single issue. Heck GM's export spec calls for ACEA A3!

And that export spec says a lot, too. General Motors engines, including the one in your Envoy, had been calling for 30 grades with low HTHS for decade after decade, although with warnings against the garbage 10w-40 offerings from way back, yet an appropriate A3 option clearly didn't spook them.
 
Originally Posted By: Snagglefoot
We’re in this together, through thick and thin.
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Wayne, you are fine. Do a UOA when this OCI is done and I'll bet there is no crazy wear and your oil filter won't be filled with metal hash from your engine getting destroyed.

In every case on here, going up one grade hasn't hurt a thing. That's all you are doing since the engine was originally designed around a 30 weight oil...

Edit: now you might not want to run a 40 in something spec'd and designed for 0w16.....
 
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Originally Posted By: Garak
And that export spec says a lot, too. General Motors engines, including the one in your Envoy, had been calling for 30 grades with low HTHS for decade after decade, although with warnings against the garbage 10w-40 offerings from way back, yet an appropriate A3 option clearly didn't spook them.


Way back in the early to mid 90's, Ford used to spec 20W-40 for Modular engines in this part of the world. Aside from Motorcraft branded oil in those white bottles back in the day, it wasn't an easy weight to find, and most people ran 20W-50 with no ill results.
 
What is supposed to happen? It is a "0" when cold so flow is not an issue and at operating temperatures it is hardly a super heavy oil. Is it optimum? Perhaps not, but ruin your engine? Not a chance.

Stop listening to those who more than likely have never even seen a bottle of 0W-40 much less used one.
 
OP, check out the recent 2018 Stinger thread with the viscosity chart. 20w50 is acceptable when the climate allows for it.

You aren’t going to hurt your truck with essentially a thick 30 weight oil.
 
Originally Posted By: Shannow
Yep, "they" always have to "contribute" to any discussion...same as "IBTL" in other threads.


Hey I didn't even post in this thread yet.
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OP no worries, that oil might even be of benefit to an older engine.
 
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