thinner oil

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I'm using 5W20 in place of 5W30, Ford back-spec'd my engine. I'm happy to report I'm using less oil with the 5w20. I've thought about why and it could be for 2 reasons: 1. The A-rx treatment freed up the rings. 2. 5w20 is made from a better base stock than 5w30, and has a higher flash point so its less likely to burn off as easily as the 5W30. That came direct from the Pennzoil tech dept. I'm speaking strictly about Conventional oils here.


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At the risk of contradicting you the example of 5w20 vs. 5w30 is not a good one. The base oil visc of both is the same at ~4cst. The only difference between the 2 is more vii's in the 30 wt., and with some usage that difference will disappear. Better would be a diesel that called for 15w40 and the O/O is using the 5w20, now this is actually thinner.
 
Sorry base oil is same and working visc is about only 10% difference, essentially the same thing, and the bottle of 20 has more oil than the bottle of 30.
 
I spoke to the good people at Pennzoil Friday about this very same topic. 5W20 is thinner than 5W30, slightly but still thinner. They wouldn't disclose base stocks, but did say 5W20 was made from a better base stock than 5W30, and is closer to a synthetic oil than the YB 5W30 is. I'm just repeating what I was told, and again referring to conventional oils.
 
There is more difference in the 30 grade, than between 20 and 30 grade.HM to regular is about the same 10% difference and both are 30 wt., and thus considered the same thing.
 
I wrote what they told me, and understand your point. Yes they're very close but they're different, and answered the OP's question about 5W20 vs 5W30.
 
I merely meant that the example presented was to narrow, and bluntly wrong. If you must split hairs, at least pick one we all can see, and not need magnification. Not to snip, but this question is just a bit off.
 
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The base oil visc of both is the same at ~4cst.


Can we take your word on that? That's lower, iirc, than what Bruce uses in my 0w-10 oil. A 5w30 ..with other massaging, can have a much higher base stock visc and still meet the 5w CCS spec's.
 
The base oil without vii's question was discussed on this board, and with saome variance the values I report are what was discussed. With your knowledge can/could you answer as to the likely max viscosity of the vii'sless base oil, that meets the cold numbers testing?
 
I believe bruce stated that with the VI of Group II+ base stocks 6-9 range ..with some massaging w/PPD's and corrective fluids would make the cold spec's. I can't recall the specific number ..but it was much higher than I thought it would be.

Many 30 grades were 20 weights massaged at both ends.

I do think that 4CST is the lowest base stock one can use without substantial increase in volatility ..or so bruce has told me when I asked if he could go even lower than a 5Cst+/- finished product.
 
Originally Posted By: t retired
anyone using thinner oil than what is called for, 5-20 in place of 5-30



To answer the OP's question, I use Amsoil 0w20 in place of a 30 wt. on my mother's Chev Venture during the winter months. The reason is because it's real cold up here and she only ever drives a mile in any direction. The oil very rarely has a chance to warm up at all. I will use the 30wt again come the summer as the van then does towing duty for me!
 
Oh ..there's an OP?
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I use 5w-20 in everything I own (or have used). I even use 0w-10 from time to time. None of them spec'd for it.


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Originally Posted By: jldcol
Sorry base oil is same and working visc is about only 10% difference, essentially the same thing, and the bottle of 20 has more oil than the bottle of 30.


You know oil formulations now?

Many 5W-20s are rumored to be stealth synthetic blends of Group III and II, or at least a II+ making it at least a borderline syn...

And 5w30 IS thicker at 100cst across the board. You are correct that some of the differences make disappear over time as the 5w30 shears. But cars using oil will probably use more 5W-20 oil. As a side note, I noticed last night that my father's Mercury uses (burns apparently) 5W-20 YB at a higher rate than the 5w30 he previously had in there..

For the thread question, it's a 99' Mercury Sable with the beefier 24 valve 3.0L 'Duratec' engine that originally spec'd 5w30, but was back spec'd to 5W-20 as an option. I used 5W-20 Pennzoil in it, and the car appears to burn through it a touch faster (about a quart in 1800 miles and 3 months of driving).

I think we'll put in Valvoline MaxLife 5w30 for summer...
 
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I used Pennzoil Platinum 5w20 in '00 MB E430 (the recommend oil is Mobil 1 0W40) last year, the engine was much quieter specially at idle. I then switched to Delo 15W40 and engine noise increase as it was with Mobil 1 0W40 before Pennzoil Platinum 5w20. The car has Mobil 1 0w20 mixed with 10W30 now, engine is quieter than xW40 but not as quiet as with Pennzoil Platinum 5w20.
 
I am considering using MC 5W-20 in my GM Ecotech 2.2L if I keep it for next winter. It's spec'd for 5w30 and 10w30 above 0F I believe...

But it uses virtually no oil despite a slight upper valve cover leak...
 
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