Stepping down an SAE grade

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How many current members successfully run their engines a grade or two below what is "recommended" in the owners manual with good/bad results? For example running 0w20 in an engine calling for 5w30, etc. Kind of similar to how this guy used Neo 0W5 in 1.9TDi for 25k miles, an engine that usually calls for 5w40 oils.
 
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I’ve seen on here a member we used to have ‘originhacker21’ ran 20-weight oil very successfully in a 2004 Pontiac Sunfire. I’m seriously thinking of running 0W-20 in my 2009 Pontiac G5, that sees nothing but short trips.
 

Vladiator

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Define "successful".
Good UOAs if possible, and/or on the same bearings for more than 80k-100k miles of "thinner" oil use.

P.S. The reason for this thread is a recent discussion with a friend about my reasons behind wanting to switch all my vehicles to 0w40 grade at 5k OCI regardless of manufacturer's recommendations for grades and intervals in 10 vehicles that I maintain.
 

Vladiator

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I’ve seen on here a member we used to have ‘originhacker21’ ran 20-weight oil very successfully in a 2004 Pontiac Sunfire. I’m seriously thinking of running 0W-20 in my 2009 Pontiac G5, that sees nothing but short trips.
Tried to find that thread with no luck, You happen to have any links?
 
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Interesting topic, but I'd still be lost with the reason: This switch of yours to 0W-40, is that meant to be such stepping down (high revving, suspect of much loss from shear, 5W-/10W-recommendations etc.) or on the contrary as stepping up?
 
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Good UOAs if possible, and/or on the same bearings for more than 80k-100k miles of "thinner" oil use.

P.S. The reason for this thread is a recent discussion with a friend about my reasons behind wanting to switch all my vehicles to 0w40 grade at 5k OCI regardless of manufacturer's recommendations for grades and intervals in 10 vehicles that I maintain.

Given the inherent limitations of UOA's such as limited resolution and inability to discern wear from chelation, when you add in the different signatures of different additive packages and base oil combinations, trying to use them in this capacity would be an exercise in futility.
 

Vladiator

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Interesting topic, but I'd still be lost with the reason: This switch of yours to 0W-40, is that meant to be such stepping down (high revving, suspect of much loss from shear, 5W-/10W-recommendations etc.) or on the contrary as stepping up?
My switch to 0W40 is more of a step-up for the vehicles that "recommend" 0w20/5w30, and the required grade that meets specs for the Euro cars (Volvo 2.5t and VW 2.0TSi). My friend is a "thin" oil addict though. I'm just trying to see if anyone on this oil forum has successfully done what he is saying everyone should do, which is to switch all their cars to 0w20 oils. I guess in a way I am trying to gather some info to present to him that it is not a good idea, but if I am wrong and people here have used thin-grade oils in cars that recommend thicker grades, and caused no issues long-term (extra wear, bearing failures, etc.), then I'll gladly present that to him as well...and continue using my 0w40 oils that meet such specs as Porsche A40.
 

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Here is my reasoning behind using M1 0W40: I have seen thousands of UOAs and testimonials here on Bitog since I joined that formed my thinking of "If an oil is good enough to meet Porsche A40, MB229.3/229.5, VW 502/505, then it should be more than enough to protect ANY of my daily driven cars". The fact that apparently many race teams use M1 0w40, regardless of what oil companies sponsor them, gives me piece of mind with that oil choice. I don't have the ability and resources to rebuild and remeasure my engine internals every few weeks, so I'll rely on the oil choice of those who do just that between races. Cheap insurance, so to say. Yes, daily driver is not a racecar, but still.

Here is the reason for this thread: I gave my friend plenty of reasons and examples behind why I am using M1 0W40 in all my vehicles, but he had a hard time explaining his reasoning behind why all cars should switch to 0w20. His main points were:
- It flows better when cold.
- Nearly all manufacturers switched to 0w20, so all cars made in the last 25 years have no reason not to use 0w20 as well.
Neither of his points were convincing enough, so I turned to the biggest oil forum to see if anyone shares and exercises the views of my friend, and could provide more convincing reasons, or factual proof, of why 0W20 grade is superior and should be used across the board.
 
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I went a grade above the recommended 5w20. I based my decision on speaking with experts and professionals who know a lot more about engines and oil than I do. Having said that I suggest anyone thinking of deviating from the fill cap or owner's manual do their own homework.
 
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AEHass
I went a grade above the recommended 5w20. I based my decision on speaking with experts and professionals who know a lot more about engines and oil than I do. Having said that I suggest anyone thinking of deviating from the fill cap or owner's manual do their own homework.

Same here.

Caterham and AEhass used to say you could do it , if you had a real oil pressure gauge, and observed that at full temp. Not a idiot type gauge. They claim as long as you have acceptable oil pressue at full operating temp, its ok.

I would not recommend it, too little return/advantage for the risk.
 

4WD

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AEHass


Same here.

Caterham and AEhass used to say you could do it , if you had a real oil pressure gauge, and observed that at full temp. Not a idiot type gauge. They claim as long as you have acceptable oil pressue at full operating temp, its ok.

I would not recommend it, too little return/advantage for the risk.
I would not do it and I’m not afraid of 0w20 … some OEM‘s made engine changes before 5w30 swap to 0w20.
Going from my 2010 5.3L to my 2017 5.3L for example: New variable output oil pump (higher pressure when accelerating), piston jets, oil cooler, higher oil capacity, and better overall cooling.
These engines have a stiff 6 bolt lower end that keeps things concentric …
Having said all that … once out of warranty I would not hesitate to bump to 5w30 …
 
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I wouldn't do it. Going up, yes,as is always mentioned in FSM's for severe operating conditions, but I've never seen a recommendation for running thinner, but have seen many warnings about doing so.
 

Vladiator

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I wonder how AEHass is doing with 0W20 oils in his exotics? But I doubt he puts 20k-30k miles per year on his cars like some of us... So don't know how applicable his experience is. Maybe once he gets over 100k on 0W20 without major engine failures on that Ferarri?
 
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many owners trade often so the wear from thinner oils is never realized as well as other issues! cleaner oil is more important with the thinner oil film from thinner oils as well!
 
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xW-20 of sound constitution need not be seen as out of this world for a vehicle requiring just_some_40 (to have a bit of spread to begin with). Such a vehicle must get along with some 0W-40 loosing much temporarily & permanently. Although HTHSV is less affected than KV100 dropping from 13+ to around 10 might insinuate, many vehicles would be fine with HTHSV around 2.8 or 3.0 as there's not necessarily much more to be had from running higher.
By this I would never suggest simply "stepping down a grade" or two, but taking realities into consideration that are not represented by the coarse grades and some more labeling, can be an option. Several 5W-30 should be seen as the less serious 5W-20 or 0W-20 overall anyway, as far as I can figure it out. From 0W-40 bling to xW-20 it became more experimental.
Unfortunately you cannot be wrong mostly ignoring this 0W-5 Volkswagen story. Not much to be had from that one of course. Or from just following your friend. Or following me when something went wrong.

From the garages I might add that rotaries originally came from the 40 grades, then as Renesis had gotten 5W-30 here and 5W-20 there. They'd become different by then, especially in that they needed high revs and showed much fuel dilution, so not much use comparing findings from the bearings, gears and else with those of the predecessors, but between the 5W-20 and 5W-30 communities the problems never really differed.
 
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I would not do it and I’m not afraid of 0w20 … some OEM‘s made engine changes before 5w30 swap to 0w20.
Going from my 2010 5.3L to my 2017 5.3L for example: New variable output oil pump (higher pressure when accelerating), piston jets, oil cooler, higher oil capacity, and better overall cooling.
These engines have a stiff 6 bolt lower end that keeps things concentric …
Having said all that … once out of warranty I would not hesitate to bump to 5w30 …
I agree, that's some nice homework. There are some vehicles made in the era where all there was, was a change in the model year, and nothing else. No internal engine changes whatsoever. Along with that change came the 5w20 spec, from 5w30 and no other oil choices. That seemed odd to me. Was 5w30 suddenly going to ruin all the engines from prior years that ran on it for many years?
 
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Not sure if it was "Saturnfan" but someone was running 0W-20 in their SL series Saturn in the cooler months at least. I believe they said they had always use syn oil and didn't have the typical burning issues those 1.9L engines are known for...
 
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I have a absolutely beautiful 94 ford conversion van bought 3 years ago with 19,800 miles. Sitting at 33,000 now.
When I bought it I wanted the best so started looking up recommended grades and so on. Looked on Amsoil sight they was recommending 0w20?? or may have been 5w20. I was wondering why then checked what ford is recommending which was the same 20 weight while my manual and oil cap show 5w30. Manual also adds 10/30 as well for cooler weather. This totally made me question everything about manufacturers recommendations. If the engine was originally designed for 10w30 why have they now switched saying my engine should run this 0w20? I ended up choosing exactly what the OP is switching his vehicles to which is mobile 1 0w40 euro blend. What led me to this is the 5.8l engine up until 94 was a flat tappet design but some of the vans did not get the new roller setup until 95. Pretty sure mine is the roller setup but I chose a oil I figured would work for both. Loving it so far.
 
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