91 Laredo

While it was nice to have every single oil change invoice when I bought my Jeep (I mean every one!), too bad it was the Penz...

raypla

Do you change the oil and filter everyh 3000 mi? Fully synthetic?

Oh back to the original question I bought my XJ from my uncle and new he had been putting M-1 in since about 20K so it was a no brainer. When I bought it in 06' and started researching more I found you could run a bigger filter w/no modifications, ever since I've been running a ford 5.0 filter, about 3/4 qt more capacity, and run the filter till about 5K when I put in a new one in add a qt or so and run it till about 10K ,give or take, then drain it and start all over. The oil looks pretty new after I change the filter and add a qt. I figure I'm not on saving money and time I'm doing better for my engine, kind of makes me feel all warm and fuzzy inside.

stumper

also, remember that tv. commercial, it's cheaper to change your oil than to change your engine. run the brand you want too, [ i am running Quaker state 10w40 synthetic] but change it often. we also have temps well below freezing up here, -30c and colder. that oil needs to flow when called upon. regular 5w30 in our temps is like heavy syrup. try this, take jug of 5w30 oil and a jug of 5w30 synthetic, put them in your freezer for a couple hours, say overnight, then try to pour them out. go on, try it. just make sure it's ok with your better half. Change your oil, it's cheap engine insurance. Stumper.

crashzx6r

PUt some 10 w 40 of your choice then add some lucas oil stabilizer its thick as molasses till it mixes i could tell big difference...also the lifters shut up.....

athenscj5

Forgive my skepticism and/or ignorance but, if the zinc and other stuff helps your engine run better, then why is it considered a diesel oil and not a high milage gas oil?

I only ask because I am wondering if my Castrol GTX 10W30 is sufficient for the 0 and below temps my Jeep is experiencing here in Kansas. Plus with the rattle I mentioned before.

antibiotics

I wonder if anyone tried Rotella syn 5W40 in XJ? This oil is highly regarded in the oil forum, Bobistheoilguy.com.

crashzx6r

Remember in side a motor is metl rubbin metal really fast....just needs a thin layer of oil...oil breaks down faster in high milage.....id run some stabilizer if your worried about your motor....only other option is to rebuild it....lol that lucas additive will help with knocks and tick maybe shut them up.... also it will help with those cold temps keeping the oil stabilized helps cling instead of just being splashed around

whowey

The reasons it is considered a Diesel Oil and and not a gas oil have to do with the EPA...

The EPA mandated lower levels of Zinc and Phosphorous in oil to reduce catalytic convertor damage from burning or leaking oil. The problem is that Zinc and Phosphorous are the two primary anti-wear additives of oil. Oils that are API:Sx rated are considered gasoline oils.. the S stands for Spark ignition. Diesel oils are API:Cx rated... or the C stands for Compression ignition.

Diesel oils are not subject to the same lower Zinc and Phosphorous levels, so Rotella can still contain the higher levels that our motors need.

As far as your concern... if you oil is API:SM rated, than no its not sufficent to use in your Jeep. The lower levels of Zinc and Phosphorous in SM rated oils are not sufficent for our flat tappet motors. We need API:SL rated oils or older.

One 10w30 at zero degrees is going to behave like another 10w30 at zero degrees. But... there is the base viscosity and the pour point of an oil to consider.

If you routinely see sub-zero temps, I would seriously consider looking at a 5w30 oil. The lower viscosity helps in the colder temps. And avoid an oil thickener like Lucas Stabilzer, its nothing more than a handful of viscosity modifing agents in a heavy base oil. It does nothing to improve the protection offered by your oil's additive package.

BowtieGuy3

Don't look at me... I use QS in everything, and the Jeeps get 5w-30 right now for winter, and a quart on Lucas.
If you want it to pour faster, nuke it for a little bit, or leave it in the sun for about 30-45 mins.

hubbazoot

I run 10w30 Gastrol (I think...) year round with a FRAM filter. That's been the combo for the last 238k miles, so it's holding up just fine

Mattster

I run 5w-40 Synthetic Rotella now, was using standard 15w40 but the synthetic is much nicer saw 2mpg gain in fuel economy from it too. Didn't change my driving style. In the Jeep I just got I put some Lucas Synthetic oil stabilizer which ate up the rear seal and most of the oil drained out the next day, luckily it wasn't run too long before I noticed the puddle of oil.

BowtieGuy3

If you want the really pimped out oil, Mobil-1 makes some seriously cool stuff, like 0w-30, and I think they might have a 5w-50...

I'm in Chicago and I use 5w-30 year round, unless we hit a especially hot summer, or I'm doing a lot of hauling, then it goes to 10w-40, or a 20w-50/Straight 50 for then.

funkle95xj

I do. And she has been fully synthetic since I've owned her. I know the previous owner kept up on the maintenance and changed the oil regularly. I'm just not sure which brand or viscosity they used...

michigan_maniac1987

i wouldn't recomend to go over 3k on a filter or oil, the filter does not stop the smaller particles after extened use, this info comes straight from pennzoil, for work i had to go to one of their meetings.

hubbazoot

I do it every 5k miles, just for the record.