Synthetic oil ? ?
CF Veteran
Joined: Aug 2010
Posts: 8,387
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From: The Florida State University
Year: 2001
Model: Cherokee
Engine: I-6 4.0 L
I've run the Rotella and the Valvoline 10-30 (I'm in South Florida). Also, I use a Mopar filter from Advanced... Can't go wrong. Your seals may be fine, but the synthetic oil might make them leak.
Secondly, Lucas oil stabilizer is CRAP!!!!!!!! Do not waste your time. There was a video on YouTube that was removed. Essentially, a few guys hook up a drill to the Lucas oil display at an auto parts store... the minute they fire it up, all it does is foam the oil. IT DOES NOT WORK.
Secondly, Lucas oil stabilizer is CRAP!!!!!!!! Do not waste your time. There was a video on YouTube that was removed. Essentially, a few guys hook up a drill to the Lucas oil display at an auto parts store... the minute they fire it up, all it does is foam the oil. IT DOES NOT WORK.
Last edited by cf1k1; Jun 8, 2012 at 08:13 AM.
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Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Junior Member
Joined: Nov 2011
Posts: 93
Likes: 0
I would not run synthetic in a saturn with that many miles. Do they leak yes but synthetics are also engineered to where the molecules are similar in size as compared to conventional oil which is made of long and short chains. Those short chains burn up faster. Molecules being the same size does two things one they withstand heat better but they also flow better which is why they run cooler. Synthetics also dont contain the wax and sulfers that conventional oil does.That is what leads to a lot of the sludge and varnish. To say synthetics are some sort of snake oil is just ignorant. People say they leak and they do if
you have bad seals, but common sense would kinda make you wonder how one oil has the ability to work through a hole that another can't. They just lubricate better. Are they worth the money depends on what and where your driving.
you have bad seals, but common sense would kinda make you wonder how one oil has the ability to work through a hole that another can't. They just lubricate better. Are they worth the money depends on what and where your driving.
CF Veteran
Joined: Mar 2011
Posts: 1,751
Likes: 3
From: Tampa Fl
Year: 1997
Model: Cherokee
Engine: 4.0 HO
Originally Posted by rrich
Fake oil's molecules are all the same size - dino oil's molecules are all kinds of sizes. The larger molecules in dino oil tend to plug small leaks better.
The hype is fake oil withstands a higher temperature before it breaks down - true. But hey Buddy, if your engine gets hot enough internally to break down real oil you have major problems anyway - it's dead!
One of the reasons we use oil in the first place is it carries heat away from the hottest parts - bearings etc. 50% of the engine cooling is done by the oil. (Read about oil coolers.)
Fake oil doesn't carry away heat as easily as real oil - parts will run hotter. People like Currie - who make the best diff gears - their warranty is voided if you use syns.
The hype is fake oil needn't be changed as often. The reason we change oil is to get rid of the contaminants from combustion. Nothing stops the burning process from producing carbon particles, water, and acids in the crankcase - unless it prevents your engine from running at all.
But - mfgrs, suppliers etc all love it - it's a very high profit item.
Drive through Texas - see all those little buildings that disappear when you look right at them? Synthetic oil wells.
Synthetic - fake truth.
Avoid oils that use gimmicks to make you think they are special - ie: Adding food coloring to oil does nothing.
Quality Oils designed for automotive use already have all the additives needed to keep it slippery and working properly. Dumping snake oils in only dilutes and can counteract the lubrication properties.
If those snake oils were beneficial, don't you think the oil companies would add them and brag about it?
OIL DESIGNED FOR YOUR JAPANESE CAR - 10-30 WITH TERRIYAKI!
FOR YOUR FERRARI - 20-40 WITH OLIVE OIL
30 WT WITH KROUT!
KimChi 20 WT
MERLOT 40?
For the younger crowd - 10WT with "Nestlies Quick!"
Use quality oil with a quality filter, change them frequently.
Remember paper and the internet don't reject words - lies and hype look real.
The hype is fake oil withstands a higher temperature before it breaks down - true. But hey Buddy, if your engine gets hot enough internally to break down real oil you have major problems anyway - it's dead!
One of the reasons we use oil in the first place is it carries heat away from the hottest parts - bearings etc. 50% of the engine cooling is done by the oil. (Read about oil coolers.)
Fake oil doesn't carry away heat as easily as real oil - parts will run hotter. People like Currie - who make the best diff gears - their warranty is voided if you use syns.
The hype is fake oil needn't be changed as often. The reason we change oil is to get rid of the contaminants from combustion. Nothing stops the burning process from producing carbon particles, water, and acids in the crankcase - unless it prevents your engine from running at all.
But - mfgrs, suppliers etc all love it - it's a very high profit item.
Drive through Texas - see all those little buildings that disappear when you look right at them? Synthetic oil wells.
Synthetic - fake truth.
Avoid oils that use gimmicks to make you think they are special - ie: Adding food coloring to oil does nothing.
Quality Oils designed for automotive use already have all the additives needed to keep it slippery and working properly. Dumping snake oils in only dilutes and can counteract the lubrication properties.
If those snake oils were beneficial, don't you think the oil companies would add them and brag about it?
OIL DESIGNED FOR YOUR JAPANESE CAR - 10-30 WITH TERRIYAKI!
FOR YOUR FERRARI - 20-40 WITH OLIVE OIL
30 WT WITH KROUT!
KimChi 20 WT
MERLOT 40?
For the younger crowd - 10WT with "Nestlies Quick!"
Use quality oil with a quality filter, change them frequently.
Remember paper and the internet don't reject words - lies and hype look real.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Here's something I stumbled upon when looking up a bulb number for the climate control for another CF member.
Jeep Engine Oil Viscosity
This was taken from pages 82 and 83 of the 1989 Chrysler/Jeep owners manual.
Selecting Engine Oil Viscosity
When changing or adding engine oil select the proper grade by using the chart on the following page. Select the grade that corresponds to the ambient temperature range you expect to encounter before your next oil change.
30*F to 100*F+ 20W-40 or 20W-50
0*F to 100*F+ 10W-30 or 10W-40
-20*F to 60*F 5W-30
Jeep Engine Oil Viscosity
This was taken from pages 82 and 83 of the 1989 Chrysler/Jeep owners manual.
Selecting Engine Oil Viscosity
When changing or adding engine oil select the proper grade by using the chart on the following page. Select the grade that corresponds to the ambient temperature range you expect to encounter before your next oil change.
30*F to 100*F+ 20W-40 or 20W-50
0*F to 100*F+ 10W-30 or 10W-40
-20*F to 60*F 5W-30
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
It's probably all fine. I use 15W-40 Rotella. Our temps can vary from 0*F to 100*F. It kinda points out that all this fuss over oil weights for a Jeep motor is for naught.
Junior Member
Joined: May 2011
Posts: 92
Likes: 0
From: By Detroit
Year: 2000
Model: Cherokee
Engine: 4.0
The Mobil1 sales at AutoZone, Oreilly's and Advance are the way to go. Mobil1 filters have some of the smallest micron ratings and we all know their oil is good...
And you can get out the door with the 5 quart jug and a filter for about $35.
I also run the bigger oil filter. M1-301 instead of the M1-204.
And you can get out the door with the 5 quart jug and a filter for about $35.
I also run the bigger oil filter. M1-301 instead of the M1-204.
Last edited by 00SportXJ; Jun 11, 2012 at 09:09 PM.
CF Veteran
Joined: Nov 2009
Posts: 8,172
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From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
Seasoned Member
Joined: Aug 2010
Posts: 294
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From: Pahoa, Hawaii
Year: 1995
Model: Cherokee
Engine: 4.0 HO K&N filter #703 injectors
Oil has to to meet minimum standards, I was a mechanic for a fleet of tour busses and we always ran what ever is on sale , as long as you you use a good filter ( I prefer WIX ) and change it as needed you should be good, remember the engine is designed to have Oil in the oil pan 
CF Veteran
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Model: Cherokee