I just read through this entire thread and all I can say is WOW! There are a few people that know what they're talking about and a ton who are just passing along some other person's narrow-minded opinion.

I think what most people want to know after reading this thread is "What oil should I use, without breaking the bank, that will provide me with the proper amounts of zinc and phosphorous?" I see that the high mileage Mobil 1 has better numbers than most, but some people like me don't want to spend $40+ on an oil change. Someone (who knows what they're talking about) please post a list of 'ideal' motor oils to use for this particular situation. BTW, I'm already using the WIX oversized filter and would definitely recommend no matter which oil you choose to run.

Thanks!

 

whoops its 91-01 for the oversized filters i posted not 89-01

just got home and checked it

 

I gots a 96 Cherokee 4.0

Ran Penzoil 10w30 conventional in the beginning, pulled the valve cover one day and tons of sludge, nothing but tar pockets.

Buddy at Dodge told me to run Penzoil Platinum through for a couple changes to clean it up a bit.

Oil pressure is better, no leaks at all. Been runnin Platinum for 10k now.

Upgraded to the sexy Aluminium valve cover and the valves looked alot better. Not 100% clean, but just cleaner overall.

Stay away from additives. If it didnt come in the motor, it dont belong in the motor.

 

Yea I hate Penzoil, and surprise Quakerstate

 

For what it's worth, I just got some O'Reillys HM 10W30 that is SL rated.

 

I changed out whatever cheap crap the previous owner had put in mine and replaced with Valvoline MaxLife 10W-30 last week. After a weeks driving the couple of small leaks I had seem to have stopped.

 

Anyone...?

 

My father always used Havoline 10w40 conventional w/deposit shield thing. The jeep has 161k miles. Can I get some opinions on this oil from you guys?

 

I swear by Castrol GTX 10W-30. I couldn't get that last time I changed oil, so I tried Motorcraft Synthetic Blend 10W-30, which is actually cheaper than GTX. No complaints. Not, that it matters much, because I religiously change at 3k miles intervals. I have, however, a habit of running motors well past 200k miles. I avoid Fram filters, and use either WIX (Napa), Bosch or STP. But the Walmart Supertech brand seems quite good, too. I am a little opposed to the long change intervals of full synthetics, since the additives break down over time and the oil gets awfully dirty, even with extra filter changes.