I have been using Mobil Clean 5000 10W-30 during the warm months and 5W-30 during the cold months. I am wondering if this is the oil that my XJ wants. I have read many posts about XJs loving zinc and whatnot, so is this oil filling my XJs needs? I hear a lot of people running Castrol, is that a better route, and if so, which type of Castrol. Help me out, I want to keep this 98 4.0 running forever!

 

Me, I personally use Castrol and have my whole life. I usually use 10-30 in the winter and (I may get yelled at but...lol) but I use "Straight 30" in the summer and NEVER have had a problem in 2 years with my Jeep. I have a mechanical gauge in my jeep and it reads 30psi at idle and 50psi at about 1500rpm and thats with 221,200 miles on it...Tj

 

I've used Castrol for a long time now, currently I use the "High Milage" version in 10-30, with a quart of Lucas Oil Stabilizer, and I like to use the K&N filters because of the nut that's on the back of the filter, makes it nice and easy to remove when it's time for an oil/filter change. I would think the Mobil stuff would be good oil though, never used it personally, but I know their synthetic stuff is supposed to be awesome. I also like Valvoline as well, and I run as fast as I can away from Pennzoil, lol.

 

I run typically run 10-40 with the occasional 10-30 of whats ever on sale that week. The 4.0 runs dirty anyways so why use a synthetic and high mileage oils are a garbage so cheaper is better for me

 

If you are worried about your oil/engine, get an oil sample run at Blackstone at the end of your OCI. If your engine has been maintained properly and is running properly, then stick with your MC 5000 regimen. If you feel you need more zinc, use Rotella 10W 30 next oil change.

 

RoyalPurple has a break in oil that has zinc in it. The new motor oils have no zinc because it damages the cat converter...so "they" say.

 

MC5000 is good oil and is designed to go 5000+ MI OCIs (hence the name) I would use it with a good filter (Wix, NAPA, Purolator, pretty much anything but Fram) and not worry...
If youre worried about your motor you could run Rotella T5 Semi-Synth, they have 10w30 and 10w40

 

I've been changing my own oil for 20 years now and always went with Super Tech 10-30 in winter and 10-40 in summer. Its a Wal mart brand and have never had a problem. My last truck I had for 13 years and Wal mart brand the entire time. Sold it to a buddy and still runs great.

 

Supertech in our area is made by "Warren Performance Products" and is pretty good oil.

 

Are Fram filters that bad? I've never heard anybody say anything bad about 'em, just curious, not being a smart@**

 

Without going into too much detail, the are cheaply made and use a "fiber" (cardboard) end cap design. Under certain circumstances the fiber end cap can get holes in it or disintegrate and allow unfiltered oil to circulate.

 

i use supertech full syn i am on a budget walmart brand!!!

 

Thanks for the info Defiance!, I used to use Fram, but now that I KNOW, I won't run 'em anymore if I can avoid it, personally I like the K&N Gold filters because of the nut on the end, making 'em easy to wrench off when it's time to change it out, thanks bud

 

Here's some motor oil facts.......long read but good info along with some motor oil myth busting.

http://www.supramania.com/aehaas/

 

Driving habits has a lot to do with oil change intervals, long commutes are actually good for the oil, newer cars with oil life indicators use this to determine oil life the longer the engine is at operating temp the better burns off the moisture, this along with a good filter you can extend OCI, I go 7500mi in my toyota, and my wifes HHR and no problems I inspect every filter after the change they always look fine. short drives, long periods of sitting. so so long winded JMO