Yet another thick vs thin oil question.

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22,653
Location
Dallas,Tx USA
Oh no! Not another thick vs thin,haha! Well here`s my question/s. I went down to a 10W40 from a 20W50 recently. 10W40: SILENT smooth startups,lightning fast acceleration through the powerband. Looking at the camshaft,oil bath is thinner and splashes off. Not as quiet on WOT runs. 20W50: Smoother once good and hot,most noticable on WOT........smooth as glass,but sluggish on a cool engine. Looking at the camshaft while running,oil bath is MUCH thicker,is saturated,and doesn`t fling off but clings to it completely. Soooooooo,if you like to drive it like you stole it,which oil is better over the long run? A thin or thick??????
 
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Messages
3,756
Location
CA
 Originally Posted By: aquariuscsm
Oh no! Not another thick vs thin,haha! Well here`s my question/s. I went down to a 10W40 from a 20W50 recently. 10W40: SILENT smooth startups,lightning fast acceleration through the powerband. Looking at the camshaft,oil bath is thinner and splashes off. Not as quiet on WOT runs. 20W50: Smoother once good and hot,most noticable on WOT........smooth as glass,but sluggish on a cool engine. Looking at the camshaft while running,oil bath is MUCH thicker,is saturated,and doesn`t fling off but clings to it completely. Soooooooo,if you like to drive it like you stole it,which oil is better over the long run? A thin or thick??????
I think you know the answer already..... That was the one thing I remember when going from a 20 to a straight 30wt in the winter with an unknown to me broken motor mount. There was ever so slightly more vibration with the 30 when dead cold at 35 degrees. No vibration with the new mount so it would've gone undetected had the mount been good.
 
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3,756
Location
CA
 Originally Posted By: Audi Junkie
Simple: You want the thinnest oil possible that does not produce excess wear.
I want the thinnest possible that does not cause any additional wear over it's thicker counterpart.
 
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25,045
Location
ON, Canada eh?
My '89 Cabriolet 1.8 Gas engine says to use 20w50 in the summer heat and to use something thinner like a 10w30 during the winter. I have used 5w50 or 20w50 in it since I got it (only drive in the summer) to curb its Low Oil pressure light affliction. (Yes I checked the pump and other mechanical parts) I found that after driving for a few hours the light still flickered on/off at the lights the same as it did with the 5w30 that the previous owner had used in it for the whole time he had it. When I took parts of the engine a part to attempt to solve the "pressure problem" I noticed that the engine was almost near perfect in terms of factory spec's and it had run the majority of it's life on 5w30 versus 20w50 as stated in the manual. (I have service records) So I agree with BuickGN's post above. BTW: It turns out this is a common problem with these models to flicker the low oil light in traffic and it should for the most part be ignored as I still have .5 bar at 950rpm idle. and 2.25 bar at 2K RPM. I also replaced the oil pump with the higher volume 2.0 litre engine pump. When I had the valve cover and oil pan off to replace the gaskets it was spotless inside and all the parts measured were close to brand new tolerances after 172K. ;\)
 
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1,093
Location
Kentucky
I have over 2,000,000 miles on various new vehicles from little 1.5L I4, DOHC, little 2.2L push-rod engines, V6 engines, and big GM V8 engines, all with Mobil 1 15W-50. I run it year round. I have one daily use truck with 300,000+ miles and one daily use car with 212,000+ miles on M1 15W-50. I have used 50 grade oils since 1963 in every vehicle I have owned. Before that I used straight Kendall 40.
 

aquariuscsm

Thread starter
Messages
22,653
Location
Dallas,Tx USA
A "pro thick oil" story I have: I knew a guy that had a base model sohc Stealth. This car was a true beater. Car had been very abused all it`s life. It had been raced,rolled (as in rollover accident from racing)and he lived out in the country and would take it in the pastures and do countless fwd donuts (didn`t know that was possible). Last time I saw him,car had almost 300,000 miles on it and engine still sounded and ran as precision as a sewing machine. He also would always shift the auto tranny as if it were an automatic (poor car!). The only time that engine never saw redline was when it was shut off and not being driven. The oil that car used all it`s life,GTX 20W50. It just blows my mind the way some people abuse their cars. Would a 10W30 have protected that poor motor as well?
 
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Messages
39,806
Location
Pottstown, PA
It's that sorta like taking a Kia and an Abrams tank and driving them both into a brick wall @ WOT and asking "Which one provided more safety to the occupant"? ..giving the impression that if you want to be safe, drive an Abrams tank ..leaving off "if you're someone prone to driving into brick walls @ WOT."?
 
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528
Location
Jupiter, florida
 Originally Posted By: FrankN4
I have over 2,000,000 miles on various new vehicles from little 1.5L I4, DOHC, little 2.2L push-rod engines, V6 engines, and big GM V8 engines, all with Mobil 1 15W-50. I run it year round. I have one daily use truck with 300,000+ miles and one daily use car with 212,000+ miles on M1 15W-50. I have used 50 grade oils since 1963 in every vehicle I have owned. Before that I used straight Kendall 40.
Your stories all over the board have persuaded me to use m1 15w50 my next oil change. Going in a flat 4.6. ;\) Currently running YB 10w40
 

aquariuscsm

Thread starter
Messages
22,653
Location
Dallas,Tx USA
 Originally Posted By: peterdes
 Originally Posted By: FrankN4
I have over 2,000,000 miles on various new vehicles from little 1.5L I4, DOHC, little 2.2L push-rod engines, V6 engines, and big GM V8 engines, all with Mobil 1 15W-50. I run it year round. I have one daily use truck with 300,000+ miles and one daily use car with 212,000+ miles on M1 15W-50. I have used 50 grade oils since 1963 in every vehicle I have owned. Before that I used straight Kendall 40.
Your stories all over the board have persuaded me to use m1 15w50 my next oil change. Going in a flat 4.6. ;\) Currently running YB 10w40
I used M1 15W50 silver cap for a long time. VERY good oil!
 
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1,574
Location
Ca, US
 Originally Posted By: aquariuscsm
........smooth as glass,but sluggish on a cool engine.
Engines run much better when oil is at Operating Temperature... wear is reduced too. So you want to get the oil reach its OT ASAP. 10W40 will reach OT faster than a thicker 20W50. Takes more time and heat to thin a 20W50 to OT.
 
Messages
39,806
Location
Pottstown, PA
I don't think they'll take more time to get to op temp. Heavier oils not only create their own heat due to their own friction, the load of pumping motor honey adds to the deal too. The initial slope of the curve may be different, but the length probably isn't too altered. You'll take longer to reach the same viscosity ...which is sorta the primary idea of lighter oils. You get a head start toward operating viscosity of a heavier oil.
 
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1,574
Location
Ca, US
 Originally Posted By: Gary Allan
You'll take longer to reach the same viscosity ...which is sorta the primary idea of lighter oils. You get a head start toward operating viscosity of a heavier oil.
Exactly.
 
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150
Location
Ohio
 Originally Posted By: Gary Allan
I don't think they'll take more time to get to op temp. Heavier oils not only create their own heat due to their own friction, the load of pumping motor honey adds to the deal too. The initial slope of the curve may be different, but the length probably isn't too altered. You'll take longer to reach the same viscosity ...which is sorta the primary idea of lighter oils. You get a head start toward operating viscosity of a heavier oil.
True, but thicker oils at op temp give you a little extra protection at full throttle when bearing loads are at their highest.
 
Messages
732
Location
Sarasota, FL
I see you like thick oils (10w40 is relatively thick, not thin) But you could use start-up protection, so try one of these: - GC 0W30 (it's thicker, like a 0W40) - Mobil1 0W40 - Eneos 0W50 - Mobil1 5w50 - Castrol Syntec 5w50
 
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