20w-50 oil

WVRigrat05

Wound for sound
Jan 1, 2011
3,081
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French Creek, West Virginia
So I changed the filter for the 6th time, the sparkles are bubbles lmao, took this filter apart with 1000 miles on it and it was spotless as well, oil pressure is good too according to the autocal, gauge is still 15 psi or so off.
 

JoeyD

WTF
Apr 21, 2008
51
0
6
Has anyone tried this Amsoil?
 

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Burn Down

Hotrodder
Sep 14, 2008
7,092
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48
Boise Idaho
Has anyone tried this Amsoil?

I just put that oil in the 05’ with the built engine on Saturday. Coolant at 190-200* my oil pressure would drop to 17 psi at idle, regular Shell 15-40. With the Amsoil 20-50 it’s holding 19-20 with the same coolant temps.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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you guys will find the oil heats up faster and pressure will eventually drop to the same as it was before IF you have not opened up bearing clearances to match the thicker oil.

thicker oil = more resistance, more resistance = more heat, more heat = thinner oil.

just going from 15w-40 dino oil to 5w-40 full synthetic i see a 10* drop in overall HOT oil temp when towing as the oil does not cause as much friction and is more consistent in keeping it at a 40wt.
 
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juddski88

Freedom Diesel
Jul 1, 2008
4,655
120
63
Chesterfield, Mass.
I used the dominator 20w-50 for a while, but cenpeco had a littler higher zinc, and cost a touch less even with my amsoil commercial acct, so I decided to run that instead. Both won't do you wrong if your clearances call for it as James said. :thumb: I've been using LE monolec 8800 15w-40 in stock clearance motors with excellent pressure results.
 

Bdsankey

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Feb 1, 2018
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Larsen, Wisconsin
I just put that oil in the 05’ with the built engine on Saturday. Coolant at 190-200* my oil pressure would drop to 17 psi at idle, regular Shell 15-40. With the Amsoil 20-50 it’s holding 19-20 with the same coolant temps.

My brand new built motor drops to 25-28psi hot idle after some WOT beat down runs with Cenpeco Super Race 20w50. At 1500rpm I have 68-70psi oil pressure hot.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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Phoenix Az
My brand new built motor drops to 25-28psi hot idle after some WOT beat down runs with Cenpeco Super Race 20w50. At 1500rpm I have 68-70psi oil pressure hot.

at what oil temp though, coolant temp doesnt tell us much as oil temp can swing 30-40* from coolant temp. was your engine setup for that oil as well?
 

Bdsankey

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Feb 1, 2018
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at what oil temp though, coolant temp doesnt tell us much as oil temp can swing 30-40* from coolant temp. was your engine setup for that oil as well?

I don't have an oil temp gauge. That being said, that was directly after driving for 30 min in 85F weather then doing 6-7 20mph->100mph WOT pulls at 1700US.

The oil reading was taking directly following the last pull at 208F coolant temp.

Yes, my engine was setup for 20W50.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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Phoenix Az
I don't have an oil temp gauge. That being said, that was directly after driving for 30 min in 85F weather then doing 6-7 20mph->100mph WOT pulls at 1700US.

The oil reading was taking directly following the last pull at 208F coolant temp.

Yes, my engine was setup for 20W50.

sadly that still doesnt give much accurate info for temp but i would speculate you to be around the 190-200* mark based on temp. Being setup for the thickness makes all the difference :D
 

Bdsankey

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Feb 1, 2018
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sadly that still doesn't give much accurate info for temp but I would speculate you to be around the 190-200* mark based on temp. Being set up for the thickness makes all the difference :D

I definitely like the oil pressure I have as well as the extra oil film thickness between the bearing surfaces.

I plan on adding a temp sensor. What port on the oil cooler/filter assy do I add it to? I know one is pre-cooler and one is post-cooler but I don't know which I need to tie into. Guess time for me to use the search function.

Even though there isn't a necessary temp reading given, the oil was most definitely hot and honestly, that is probably the hottest condition my oil will see and we can agree that isn't the easiest situation. Sure it is not a towing condition but the pistons/engine definitely got hot.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,485
467
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Central OH
you guys will find the oil heats up faster and pressure will eventually drop to the same as it was before IF you have not opened up bearing clearances to match the thicker oil.

thicker oil = more resistance, more resistance = more heat, more heat = thinner oil.

just going from 15w-40 dino oil to 5w-40 full synthetic i see a 10* drop in overall HOT oil temp when towing.

And yet by your own reasoning you shouldn't have seen a drop at all. Both xx/40 oils
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,644
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Phoenix Az
And yet by your own reasoning you shouldn't have seen a drop at all. Both xx/40 oils

yeah i should have worded that better. the synthetic will work better and will not cause as much friction acting closer to what a thinner oil would do and keep temps a little lower. i can still get both "hot" but the synthetic will cool off faster and hold a lower temp longer. the reg dino oil doesnt like it as much. not as "fair" of a comparison but something i can noticeably repeat in the truck