Different brand oil and much better oil pressure from it

Area for post regarding Jeeps other than an FSJ. This area may contain technical post regarding those vehicles as well.
Post Reply
User avatar

Topic author
Phils67
Posts: 1011
Joined: Sat Mar 24, 2018 3:11 pm

Different brand oil and much better oil pressure from it

Post by Phils67 »

Today I was at the Home Depot and figured I'd grab a few big jugs of oil to change the Gladiator and the XJ (both with a 4.0). Normally I use Mobil 1synthetic 10w30 with a Mopar MO-090 filter which I buy by the 12pks. My Gladiators 4.0 idled around 43 psi and my XJs usually idled really low around 18psi. Today I bought Pennzoil Platinum full synthetic 10w30 since they didn't have Mobil 1 and my truck is now idling at 58psi and my XJ at 40psi. 3 years owning that XJ I've never had oil readings like that, and ive used Castrol as a substitute in the past a couple times. Think I'll stick with this brand going forward. Happy with the pressures as now the XJ is more where it should have been all along. I just wanted to tell someone this because it makes me happy and everyone I know around here could care less about my jeeping and shop antics.
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
User avatar

devildog80
Posts: 1016
Joined: Wed Apr 13, 2022 2:41 pm
Location: Apache Junction AZ

Re: Different brand oil and much better oil pressure from it

Post by devildog80 »

But we do care......and keeps us coming back for the next session :)
'81 CJ5 Base, 258 I6, MC2100, T176 4 spd, 300 TC, D30 Front NT, 3.31, 2-Piece AMC 20 rear NT, 3.31, 4" high arc spring lift
'84 Grand Wagoneer, 401 V8 (.030 over), MC2150 HA Comp, 727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT - WT 3.31, 4" high arc spring lift
Rather be driving, than waiting to be modified

will e
Posts: 5087
Joined: Sat Aug 18, 2012 8:21 am

Re: Different brand oil and much better oil pressure from it

Post by will e »

We are here for you. :)
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

weeegoneeer
Posts: 229
Joined: Wed Apr 26, 2017 10:34 am

Re: Different brand oil and much better oil pressure from it

Post by weeegoneeer »

Somewhat related, I've been using amsoil z-rod 10w40 and after long highway runs my oil pressure would get scary low at idle. Dropped some napa 10w40 dino oil in it before a 1,000 mile trek back home and highway/idle pressures are much improved. One would think the oil rating describes actual viscosity at differing temps but there's something else at play here.
1984 GW

candymancan
Posts: 3602
Joined: Tue Mar 22, 2016 11:32 pm

Re: Different brand oil and much better oil pressure from it

Post by candymancan »

I will throw something out there.. that high idle oil pressure is wasted oil pressure that bleeds offand can actually cause more lubrication issues than good. Just an fyi. 58 at idle is way too high in my opinion especially if thats a HOT idle in drive

With my continious rear main seal leak.. I cant try other oils as its a waste of money.. but id like to try oils other than the walmart special. Maybe if the penzoil is on sale lol.

But i am curious now because i used to put castrol gtx or valvoline blend in ny 90. And my oil pressure was like 20 at idle after highway driving and 50-60 driving

And with walmart oil itll go below 10 sometimes which i hate and 45-50 driving.. . I didnt think much about brands of oil and viscosity at temps.

I know project farm on youtube tests oils for this. Ill have to look at his vids and see what he came up with.
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

sierrablue
Posts: 1206
Joined: Wed Nov 30, 2022 8:02 pm
Location: MN/CO

Re: Different brand oil and much better oil pressure from it

Post by sierrablue »

Don't worry I've gotten the same feeling with a bunch of my posts and stuff.

I would be questioning the actual viscosity of the oils. Either Mobil 1 is lying or the other brands are lying. Something ain't right.

I also agree with candymancan--58 psi is WAY too much for a low-end torque engine. I highly doubt you're revving it to the moon; it's not a 8000+ rpm racing engine. Even if it does hit that kind of speed, it shouldn't be frequent enough to need that kind of pressure.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.

OldFarmTruck22
Posts: 243
Joined: Sat Mar 05, 2022 4:35 pm

Re: Different brand oil and much better oil pressure from it

Post by OldFarmTruck22 »

15w-40 Shell Rotella. High zinc
6 quarts for the AMC 360
78 FSJ AMC 360 Quadratrac

candymancan
Posts: 3602
Joined: Tue Mar 22, 2016 11:32 pm

Re: Different brand oil and much better oil pressure from it

Post by candymancan »

Well i will add i went back to the F1 0-40 Valvoline oil from the cheapo 10-40 walmart oil.

And oil pressure is back to 20 psi idle HOT and 50 driving versus well 5 psi hot idle and 35-40 driving.. I knew something was up i just wasnt sure if it was the engine or oil or oil filter.

Start ups are also dead silent versus the racket the walmart oil made for a split second.
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
User avatar

Harry Dawg
Posts: 308
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Re: Different brand oil and much better oil pressure from it

Post by Harry Dawg »

I've been using O'Reilly's brand oil, just because I have become a bit of a miser now days.

After some digging, it looks like Omni is the manufacturer, but I haven't heard much about this company or the quality of their oil.

I do get a little chatter on the first start of the day, but only for a few seconds.

I have heard Pennzoil uses wax additives, so I have always stayed away from it.

Given the option, I would use Valvoline.

10W-30 year round just for better pressure and most of my rigs burn oil lol.



Sent from my Pixel 4a (5G) using Tapatalk

1968 J3500 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist
User avatar

Stuka
Site Admin
Posts: 11775
Joined: Thu May 12, 2011 5:53 pm
Location: CA
Contact:

Re: Different brand oil and much better oil pressure from it

Post by Stuka »

Harry Dawg wrote: Mon Jul 10, 2023 6:12 pm I've been using O'Reilly's brand oil, just because I have become a bit of a miser now days.

After some digging, it looks like Omni is the manufacturer, but I haven't heard much about this company or the quality of their oil.

I do get a little chatter on the first start of the day, but only for a few seconds.

I have heard Pennzoil uses wax additives, so I have always stayed away from it.

Given the option, I would use Valvoline.

10W-30 year round just for better pressure and most of my rigs burn oil lol.



Sent from my Pixel 4a (5G) using Tapatalk
Omni just repackages oil from Mobil, Exxon, and Shell. So I would assume there is some inconsistency bottle to bottle.

As for Penzoil, it used to have issues, but that was decades ago. They used high sulfur oil, and added paraffins to it. So it did get a reputation for sludge buildup. But to my knowledge, that is simple not the case anymore. Shell purchased Penzoil in 2002, and at some point after that Penzoil and Quaker-State just became repackaged Shell.

I have actually used Penzoil full Synthetic in my JKUR for the last few oil changes, and its been fine.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

sierrablue
Posts: 1206
Joined: Wed Nov 30, 2022 8:02 pm
Location: MN/CO

Re: Different brand oil and much better oil pressure from it

Post by sierrablue »

I've been running Mobil 1 motorcycle 10W-40 oil from Autozone. It's 4-stroke, synthetic, has almost as much zinc as the Valvoline VR-1, and is the same price as the name brand 10W-40 conventional. Seems to be doing well.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
User avatar

ghcoe
Posts: 1227
Joined: Sun Nov 03, 2013 6:39 am
Location: SW Idaho

Re: Different brand oil and much better oil pressure from it

Post by ghcoe »

I have been running Rotella 15-40 in all my older flat tapped engines for years now. AMC 360cid, 4.0L and an Opel 1.9L. Walmart is usually the cheapest for it.
SW Idaho Overlanding Facebook: https://www.facebook.com/SWIdahoOverlan ... page_panel
SW Idaho Overlanding Youtube: https://www.youtube.com/channel/UCYuRx2 ... wVwZJ5oztg
1977 Jeep Cherokee WT
All-Terrain T/A® KO2
Safari Kit
Factory Brush Guard
Factory Tire Carrier
Custom Roof Rack
User avatar

fulsizjeep
Moderator
Posts: 5012
Joined: Sun Nov 06, 2011 7:21 am
Location: Fruitville, FL
Contact:

Re: Different brand oil and much better oil pressure from it

Post by fulsizjeep »

I'm a big fan of Rotella 15-40 and Napa gold filter for my well used 1976 401. Not a fan of synthetic or blended oils for these old iron engines. To each his own though.
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac

sierrablue
Posts: 1206
Joined: Wed Nov 30, 2022 8:02 pm
Location: MN/CO

Re: Different brand oil and much better oil pressure from it

Post by sierrablue »

Yeah I gave up on the synthetic pretty quickly. Now I'm running the Motorcraft diesel 10W-30 because it's super high zinc w/o being so thick it bogs everything down.

I like the K+N premium and the Bosch Premium filters, although I'd run Motorcraft if I could find a big one for the Buick.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
Post Reply