Hey all, i have a jeep cherokee with a 4.0 and 160,000 miles on the vehicle. The motor itself doesnt have that many but there is no real way in knowing what the used motor that was put in had on it. I need to change my oil soon. I live in wisconsin and in the next few months its not unusual for it to get about -10 and stay there for a week. I normally use 10w30 dino. People tell me i should use 5w30 and some say i should also be using 10w/5w40. What do you think i should be running. Is it worth converting to synthetic? Thanks.
Jeep 4.0
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It is worth converting to synthetic if your oil change intervals (OCI's) are past 5k miles.
Try Valvoline Maxlife 5-30. It's 12-18% PAO synthetic, though not marketed as a blend.
It's good stuff and I have used it many times. I use the Syn version now.
If you want to go Syn, try Valvoline Maxlife Syn 5-30 or Mobil 1 0-40. Both can be found at Wal-Mart in 5qt jugs for $21.
Welcome to the forum.
Try Valvoline Maxlife 5-30. It's 12-18% PAO synthetic, though not marketed as a blend.
It's good stuff and I have used it many times. I use the Syn version now.
If you want to go Syn, try Valvoline Maxlife Syn 5-30 or Mobil 1 0-40. Both can be found at Wal-Mart in 5qt jugs for $21.
Welcome to the forum.
Since you live in wisconsin, i would definitely do 5w30 all year round (given that your owner's manual specifies 5w30). As for synthetics, NO because i hear too many horror stories about people switching to syn at 100k miles and developed bad leaks. I dont want you or any other people to experience what i went through. i switched mine at 120,000 miles with bad leaks. Still has bad leaks, and now my coolant temp. is rising to the half mark when i accel and goes down to normal when i decel or when i turn on the heater. Use a good 5w30 dino oil like Havoline, Castrol, or Chevron and change oil/filter every 3,000-4,000 miles.
I've read that 10w30 is too thick when outside temps. are below 0 degrees. Upon cold startup, if you dont have a thin enough oil, engine wear is impressive. About 60% of engine wear happens upon startup so protect your vehicle during those harsh winter temps.
I've read that 10w30 is too thick when outside temps. are below 0 degrees. Upon cold startup, if you dont have a thin enough oil, engine wear is impressive. About 60% of engine wear happens upon startup so protect your vehicle during those harsh winter temps.
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I would first ask what your driving routine is like. Short trips ...long commutes ...bumper to bumper ..city ....etc.
RoZzo,
I use Castrol GTX 5W30 in the winter in my Jeep. New England is weird (I mean pissah) in that it could be -20F for a week and then 50F the next. 5W30 has you covered. In the spring/fall I use 10W30 and sometimes I use 10W40 in the summer. My Jeep sees 90% trail use and is changed often due to it's beatings.
You're probably going to get a bunch of recommendations here, but I would say stick with a good 5W30 dino year round if your Jeep is a daily driver.
I use Castrol GTX 5W30 in the winter in my Jeep. New England is weird (I mean pissah) in that it could be -20F for a week and then 50F the next. 5W30 has you covered. In the spring/fall I use 10W30 and sometimes I use 10W40 in the summer. My Jeep sees 90% trail use and is changed often due to it's beatings.
You're probably going to get a bunch of recommendations here, but I would say stick with a good 5W30 dino year round if your Jeep is a daily driver.
A 10W30 should work fine for you if your Jeep is just a daily driver/commuter. If it gets really hot&humid in the summer or you "abuse" your Jeep off road during the spring and summer, I'd run a 5/10/15W40 in it.
edit-I'd probably run a 5W30 in the winter if your Jeep sits outside (not garaged) overnight. This will help the oil get up to the valvetrain a little quicker.
edit-I'd probably run a 5W30 in the winter if your Jeep sits outside (not garaged) overnight. This will help the oil get up to the valvetrain a little quicker.
Someone earlier said the owner's manual calls for 5w30 - I don't think it does. Jeep 4.0's call for 10w30 .... I've seen this in Grand Cherokees, Cherokees, and Wranglers.
However, living in Maine, I do run 5w30 in my wife's 4.0 Wrangler year-round.
However, living in Maine, I do run 5w30 in my wife's 4.0 Wrangler year-round.
I have a 96 Cherokee with right about the same mileage. UOA's show better numbers (especially Fe) with XW-40 weights. I run Amsoil 10W40 year round with no problems starting in sub-zero temps.
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Under the factory recommended OCI, 5w-30 has qualifications. 10w-30 has PREFERRED after it. This is due (this is opinion) the length of the OCI (7500 ..or was it 6000
) where a 5w-30 would probably shear to a 20 weight. 4.0 doesn't do the lightweight two step.
But if you're a 3k/3m type ..then a 5w-30 is not an unwise choice. If you're into extended drains (which would include the factory recommened OCI under BITOG standards) ..I'd advise against even a synth 30 weight ...perhaps GC would be okay.
But if you're a 3k/3m type ..then a 5w-30 is not an unwise choice. If you're into extended drains (which would include the factory recommened OCI under BITOG standards) ..I'd advise against even a synth 30 weight ...perhaps GC would be okay.
Pick a 5w30 dino for the winter months. In the summer, a 10w30, 10w40, 15w40 HDEO, etc... will work just fine. There is plenty of thought that a 40 weight oil is the way to go in the 4.0. I used to be on that bandwagon, but have since reverted to running 5w30/10w30 oils. I've started to see less and less difference between the xw30's and xw40's, so I'll stay with the more common (until I change my mind!
)
Rozzo
I have a few Jeeps with the 4.0 and over 100k
I live in Ohio and what works for me is the following
During the winter I run 5w30 and summer I run 10w40
As for brand I did run Mobil 1 but now just run Wall mart Synthetics and have not had any trouble at all
oh and this is true for my Comanche that now has 192k and I started synthetic at 150k and no problems. And “I didn’t believe till I seen it myself” I got a honest 2mpg bonus when I started to use synthetic so I figure that pays for the extra cost of the oil
I have a few Jeeps with the 4.0 and over 100k
I live in Ohio and what works for me is the following
During the winter I run 5w30 and summer I run 10w40
As for brand I did run Mobil 1 but now just run Wall mart Synthetics and have not had any trouble at all
oh and this is true for my Comanche that now has 192k and I started synthetic at 150k and no problems. And “I didn’t believe till I seen it myself” I got a honest 2mpg bonus when I started to use synthetic so I figure that pays for the extra cost of the oil
4.0 from my experience likes a 40wt oil unless it's always short trip driving. I really like rotella syn 5w-40 in ours-engine is quieter, less oil consumption, no difference in MPG. This also will cover your variance in temps.
Yeah like it gets to -20f in Mass very often, especially for a week.
People from the Northeast and also the media love to make a big deal of cold/heat snaps in the NE, when in fact the climate is more moderate than most of the midwest/plains states, that see a lot more inclement weather. Darn east coast bias. I am not picking on you.
Yeah like it gets to -20f in Mass very often, especially for a week.
Strjock81
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posted January 05, 2006 12:56 PM
"Yeah like it gets to -20f in Mass very often, especially for a week. People from the Northeast and also the media love to make a big deal of cold/heat snaps in the NE, when in fact the climate is more moderate than most of the midwest/plains states, that see a lot more inclement weather. Darn east coast bias. I am not picking on you."
Please don't contaminate this guys thread with useless "Oh, my weather is worse than yours" junk. If you want to argue weather, start another thread in off-topic. Thanks. Have a nice day.
Member
Member # 5595
posted January 05, 2006 12:56 PM
"Yeah like it gets to -20f in Mass very often, especially for a week. People from the Northeast and also the media love to make a big deal of cold/heat snaps in the NE, when in fact the climate is more moderate than most of the midwest/plains states, that see a lot more inclement weather. Darn east coast bias. I am not picking on you."
Please don't contaminate this guys thread with useless "Oh, my weather is worse than yours" junk. If you want to argue weather, start another thread in off-topic. Thanks. Have a nice day.
My wife's Cherokee has about 117,000 on it. I switched it from Penzoil 10W30 to Mobil 1 10W30 about 7,000 miles ago. No ill effects. No leaking, no new noises, etc. The pressure gauge still shows the same pressures as when it was new. Didn't notice a big difference in mileage, but it isn't the car I drive every day and my wife doesn't bother with recording the minor details. We've owned this vehicle since it was new in July of 2001, and most of the miles are highway miles.
Northern MO does have its cold days, but not so cold as MI or MN or MA or ME; it also spends nights in a heated garage so it isn't exposed to cold soaking. Might go 5W30 if it were colder or spent more time outside.
Northern MO does have its cold days, but not so cold as MI or MN or MA or ME; it also spends nights in a heated garage so it isn't exposed to cold soaking. Might go 5W30 if it were colder or spent more time outside.
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Look guys ..there are millions of 4.0's that used 30 weight oil for over 100k and showed no "ill effects". Aside from the higher FE that is typically shown with 30 weight oils in UOA (keeping mind that visc designations are broad and a 30 weight can be just shy of a 40 weight or just shy of a 20 weight) there's no reason to think that this condition is going to destroy the engine or cause it any issues over extended ownership (100k+). Surely nothing that severe. Even the higher wear marker ..left untended... is probably factored into some life cycle calculation and won't come to bear until the 3rd owner drives it for a few years.
This engine has been virtually (aside from head/flow/fuel management) unchanged for about 30 years. It spec'd 20w-50 at one time ....the owners manuals "quietly" caution against 5w-30 in some instances as late as 2002 (maybe later).
Read between the lines.
This is a very old engine that was spec'd for heavier oils for some reason. You will see this engine retired without ever getting a 5w-20 spec on it ...at any length OCI. Why do you think that is
So, by all means, use what you want, but be "aware" and not just blindly using anything and implying "nothing went wrong" is a bona fide standard of preferred suitability for an application.
This engine has been virtually (aside from head/flow/fuel management) unchanged for about 30 years. It spec'd 20w-50 at one time ....the owners manuals "quietly" caution against 5w-30 in some instances as late as 2002 (maybe later).
Read between the lines.
This is a very old engine that was spec'd for heavier oils for some reason. You will see this engine retired without ever getting a 5w-20 spec on it ...at any length OCI. Why do you think that is
So, by all means, use what you want, but be "aware" and not just blindly using anything and implying "nothing went wrong" is a bona fide standard of preferred suitability for an application.
My 1995 Jeep GC was bought new and changed to Mobil 1 10w30 at the first oil change. My nephew now has the Jeep with 197,000 miles. Rear oil seal was replaced at ~ 80,000 & 140,000. Valve cover has never been off. If I had a new 4.0 today I would consider Mobil Truck 5w40 oil after the breakin or at about 50,000 miles.
1997 grand cherokee runs mostly on regular maxlife 10w30 and havoline high mileage 10w30 both are great oils. check my uoa with reg. maxlife came up almos perfect.
Gary, appreciate your comments and I'm sure that you're right when you say that thin oil is a bad thing in an AMC I6. No desputing that.
But I was thinking about this over the weekend and had the following thoughts:
When was the last time that AMC recommended a 20W50 for this engine? Oil has improved quite a bit since then, wouldn't you agree?
Also, there's no reason why the current manufacturer can't/couldn't have made subtle changes to the engine. Indications are that they have - the 2001 model that I currently own uses a coil bar instead of cap, rotor and wires (and a jolly nuisance to swap out plugs it is, too.)
The Old International standing up in the yard is sporting "new" aluminum pistons that are very different from the original iron ones that I took out. Both sets have "IHC" cast into them so I know that they aren't after-market. That engine's 60 years old.
Is it so far out that Jeep would spec different pistons with a tighter tolerance? Or tighter tolerances on the mains and con-rods? We know they've made changes to the heads over the years. Wouldn't certain changes allow for thinner oil?
Just musing here . . . .
But I was thinking about this over the weekend and had the following thoughts:
When was the last time that AMC recommended a 20W50 for this engine? Oil has improved quite a bit since then, wouldn't you agree?
Also, there's no reason why the current manufacturer can't/couldn't have made subtle changes to the engine. Indications are that they have - the 2001 model that I currently own uses a coil bar instead of cap, rotor and wires (and a jolly nuisance to swap out plugs it is, too.)
The Old International standing up in the yard is sporting "new" aluminum pistons that are very different from the original iron ones that I took out. Both sets have "IHC" cast into them so I know that they aren't after-market. That engine's 60 years old.
Is it so far out that Jeep would spec different pistons with a tighter tolerance? Or tighter tolerances on the mains and con-rods? We know they've made changes to the heads over the years. Wouldn't certain changes allow for thinner oil?
Just musing here . . . .
My owners manual for my '88 Cherokee specifcally recommends 10w30 SF grade Oil on a 7500 mile OCI (1/2 that for "severe") from whatever hi temp to 0 degrees F. It recommends a 5w30 for temps below zero, but under max temps of 60 F. It also "allows" the use of all sorts of other heavier oils with varous low temp recommendations.
I'll agree on the fact that a huge percentage of these motors run for a long time on nothing but good old 10w30. I was once on the bandwagon that thicker was better in these, but have since backed off some, to the point I have reverted back to using xw30 oils again. IMHO, I've seen enough good UOA's on xw30 oils to conclude that an xw30 oil works just fine in this application, is easier to find (around here anyways), and allows me to use the oil interchangable with the other vehicle in my fleet, which dislikes 40 weights from a fuel mileage perspective.
I'll agree on the fact that a huge percentage of these motors run for a long time on nothing but good old 10w30. I was once on the bandwagon that thicker was better in these, but have since backed off some, to the point I have reverted back to using xw30 oils again. IMHO, I've seen enough good UOA's on xw30 oils to conclude that an xw30 oil works just fine in this application, is easier to find (around here anyways), and allows me to use the oil interchangable with the other vehicle in my fleet, which dislikes 40 weights from a fuel mileage perspective.
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