Ok so I talked to one of the guys I work with and he said I shouldn't go lower then 10w-30. So now I have to go with my gut. I wont be doing the oil change until next week so I am open to opinions still. I too do not know if my jeep is running on conventional or synthetic right now, so I will be going with synthetic just in case its already running on synthetic. I do know you can switch from synthetic to conventional bc it wont run the same.

 

Not a pro on the subject but I dont think it matters now a days as far as switching from conventional oil to synthetic.Synthetics have come a long way tech wise.

 

http://www.bobistheoilguy.com/motor-oil-101/ oil viscosity is a VERY misunderstood thing. People telling you not to go less then 10-30 are of the old school train of thought which has been generated by opinions and old wives tales. Read the above link and educate yourself. I wouldn't ever run anything thicker then 5-30 again.... even in my 66 mustang. Also as stated above synhetics have come a long way and are fully compatible with dino oil.

 

Ok so I went to the site and started reading and I am still confused if not more confused by it.

 

Basically all motor oil (within reason) has the same thickness at temp. The difference is the thickness when cold. ALL oil is too thick to properly lubricate when its cold but lower viscosity (5-20 5-30 or even 0-20 or 0-30) is thinner cold and takes less time to get to the appropriate thinness to lubricate properly. Thicker oils do not fix things like lifter tap and rod knock as people believe, it just covers up the noise and reduces lubrication at start up causing further wear. The only actual way to fix tap and slap and knock is to physically open the engine and change the parts.

 

Ok so basically you are saying 5-30 would be good bc it properly lubercates.

 

I've always used 5 quarts Valvoline Max Life High Milage 10w30 and 1 quart MMO in all my XJ's. 2 of them are now hitting on 300,000 (287,??? & 263,???) the other 2 are right at 200,000 miles... Never had any engine issues at all with any of them.

 

if you go with full syn you can squeeze 5k out of an oil change. i recomend you seafoam it a few days before you do the change

 

5-30 is great. Like I said I use 5-30 soon to be 5-20 in my 21 year old jeep. It runs beautifully

 

in reality you want the thinnest oil you can find. otherwise your gonna cause alot of undue wear and tare on your engine

 

Everyone wants to over engineer a simple oil change.

BOTTOM LINE, do what the manual says

10w-30 ........you dont need lucus, sythetic, amsoil etc.......

Its a frickin Jeep, do what I do, use walmart oil and filter

You can squeez 5000 mile with any conventional oil

 

Im not trying to over engineer. I'm stating the facts. What you do with it is up to you.

 

x2 imo

 

What do you mean by seafoam it?

 

X3
I use Castrol. That’s just my preference.
10W-30 in the summer
20W-50 in the winter
Fram filter. Again my preference.
Seafoam every third change.