CdnJeepDan

Pretty much any off the shelf oil will meet MS-6395. They usually state it right on the bottle.

ormandj

Your rings are seated well before your 1000mi oil change, in this example. There's not going to be any hone left on your cylinder walls.

What you really need to be careful of during break-in is glazing. Just make sure to heat cycle the engine appropriately (vary RPMs, drive hard, drive soft, drive hard, drive soft, so on and so forth - no highway cruising or WOT throttle for extended periods of time) - if you glaze up your cylinder walls, you very well may have rings that don't seat as ideally as possible. Either way, there's no more ring-seating going on at the 1000 mile initial oil change you suggested. Another member suggested Bob is the oil guy, I highly suggest that website as well. You'll learn all kinds of things you'd never have known from that site. Often times experience IS correct (your method may very well have worked well, I'm not about to tell you that what you experienced isn't true) - but the _reason_ for the experience may not be that which we anticipated.

Redman333

Synthetic oil has additives that start to break down at different mile intervals based on what the oil is designed to do. Most regular synthetics the oil additives will break down at around 3000 miles and then your left with regular crude oil which most experts say replace regular crude oil between 3-5k miles depending on driving habits. Now I wouldn't suggest going 6k miles with regular synthetic but I think 5k would be fine. Some oils say you can go longer than that like 10k and even up from that. I personally don't want to go that far even if it works. I figure I'll pay for 1 extra oil change in there if it keeps me from having to replace an engine. Also when I had my 350z I had my synthetic oil tested at differrent mileages and at anything above 4500 on that particular engine with mobile one synthetic I started to see an increase in metal in my oil. I haven't ever tested the oil in my jeep though.

hdman1216

Just read the owners manual. It is in there.

aaronstephen

Jeep

Jiblet

Any oil with a current API rating (SJ through SN and beyond) will meet MS6395. Conventional or synthetic.

Or current ILSAC (GF5??) etc. etc. The bottles will tell you, just like that Pennzoil someone posted above.

I think the pentastar is more particular about oil weight than the 3.8s but I don' have one, so I don't know for sure.

powrsurg

DOing my first oil change tomorrow. Just picked up Royal Purple 5w-30. Hope I didt waste money in spending so much on the oil.

Hal9000

I have used synthetic in all my cars for 30 years. I have always considered synthetic oil changes to be the cheapest way to avoid problems. I usually change at 1000 then 3000 then every 4000. With the heat and lub requirements of these 3.6 Pentastars I really think only the best will do. In the past I have had a small compact. I only used Mobil 1 5w-30 in it from 1000 miles. It now has 160K on it and pulling off the valve cover (3 cyl) it is as clean as the day I bought it new.

Good synthetic oil and frequent changes is the cheapest maintenance you can get.