|01-18-2007 07:01 AM|
|skeeter||An easy way to find out if it'll last or not is to have it analyzed, it's fairly inexpensive and can give you some valuable information on how your engine is doing, I used to do it when I owned my own semi, when your oil changes are $150 a pop and the book says you need one every month you try and stretch em as far as possible.|
|01-17-2007 11:23 PM|
|ct-tj||Just make sure you flush the system. Ive heard some horror stories with the synthetic separating from the normal oil + turning to a foamy milk.... kinda like coolant in your oil.|
|01-17-2007 01:18 PM|
|01-16-2007 07:05 PM|
Not all companies ship thier new cars with synthetic, most of them are just going to lighter wieghts... and some are only avail in a synthetic formula such as a BMW takong 0W-30. Synthetics do resist heat a little better but wont last you another 10K between changes.
I donno about the break in time for a Jeep 4.0L... but on the Toyota 3.0L I-6 motors, it was somthing like 20-30K break in time. My friends mom has a 1995 Lexus SC300 that has 245K on the clock and still runs strong. She didn't start using synthetic untill 80K and has only needed regular maintnance on it.
If you do decide to go the synthetic route, I'd go for Royal Purple.
|01-16-2007 05:17 PM|
|ct-tj||Im using synthetic my diffs... it quited them down quite a bit. I also just switched to it in the engine too, but Ill never trust the claims of 15k between oil changes.|
|01-16-2007 04:45 PM|
I've been using quaker state synthetic blend for 4x4's and Frams tough guard filter since I bought my Jeep brand new 7 years ago. No problems after 80K miles so far. Just after you go synthetic, I hear it's a bad thing to go back to regular oil.
|01-16-2007 12:21 PM|
|01-16-2007 10:51 AM|
|bmxstreet15||When ever you switch to synthetic make sure that you get all the conventional oil out of the engine. Once you go to synthetic you can never go back. If you mix conventional oil with synthetic oil it WILL form sludge. SO when you change to synthetic let the oil drain for a good couple hours to make sure you get as much of the old oil out as possible.|
|01-16-2007 08:30 AM|
From what I was told when I purchased a new Dodge Cummins diesel years ago, the synthetics don't allow for proper seating of moving parts in a reasoable amount of time.
All engines are too tight when first assembled and need to "break in" the moving parts need to form to one another and the synthetics make that process take far longer than it should, until that happens you expend a great deal of your potential energy in friction.
My Dodge went from 16 mpg to 24 mpg highway at about 16,000 miles but it's the only new vehicle I've ever owned and I've never done a side by side comparison of 2 engines running the different oils to see if there's any truth in what I was told.
BTW, don't base any decision on what the factory does, drive trains today will easily outlast the warrenty even with no maintenance barring defects in design or material.
|01-16-2007 07:17 AM|
I'm sure the advantages of synthetic oil would be evident no matter when you changed to it. 9000 miles makes sense, unless anyone else has information they want to give us...
Again, thank you for taking the time to reply.
|01-16-2007 05:48 AM|
|gcdcpakmbs||I'm changing to synthetic on my 9,000 mile change. Waiting simply for the same reason you described. I don't know authoritatively, but I have heard the same from a mechanic that owns his own shop and races. As good as oils are today, I can't see how running it for 10K can hurt.|
|01-16-2007 01:26 AM|
I've read in these forums that many people noticed a marked increase in fuel economy after 10,000 or more miles on a 4.0 engine. This would seem to mean that the engine is not fully broken in until that point. WHAT do you all think about using Mobil One or some other synthetic before that point? (A few people have told me that you shouldn't use a synthetic oil until the engine is broken in, but Mobile's website says that some car manufacturers including Porsche and BMW are using synthetic oil from day one, at the factory..) My 2006 Wrangler 4.0 is almost to 3,000 miles and I'm wondering whether or not I should wait to use synthetics. Also, what is your opinion of the best synthetic oil out there?
As always, thank you very much for your time and your help.