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Switch to synthetic oil or not?

32K views 108 replies 56 participants last post by  Majnoon 
#1 ·
Just did the first oil change since getting my 97 Wrangler. I was considering switching to Mobil 1 Synthetic since it was on sale, but ended up staying with standard. Anyone recommend or not recommend this? Btw theres around 78k on the engine.
 
#3 ·
Change to synthetic. In addition to listening to the engine sound, look at your oil pressure, and your temp guage. With you living in Chicago, winter start-up will be easier in bitter cold. Only draw back that I have with synthetic during the winter, it takes a lot longer for the engine to warm-up, so heat also takes a while.
 
#4 ·
Mostly just a habit is why I run both my Jeeps with Mobil 1 synthetic engine and diff oil.

Ran it with prior vehicles and it served me well so i stick by it.I do the changes myself since its so easy to do.
 
#6 ·
I'm running my 97 TJ 2.5L with Royal Purple Synthetic. When I switched to RP synthetic, my jeep had about 86k mi in 2008 and I only did the basic oil and filter change. I wasn't quite sure if I was supposed to flush other fluids out before switching to synthetic. My Jeep is now 108k mi but I haven't noticed anything "weird" since switching so I take it, everything's working just fine.

I had someone told me that once you go synthetic...you can never go back to regular oil? Is this true?
 
#8 ·
Not true, you can even mix the two if needed :)

I've been running Mobil 1 high mileage synthetic because it has higher zddp levels than some other oils (anti wear additive). However I've heard that this oil does not retail its zddp levels as well as other oils, not sure if this is true or not.
 
#9 ·
What you are asking is a matter of opinion not fact but synthetic reduces friction and increases fuel efficiency. It is the opinion of everyone before me that M1 Full Synthetic is the way to go.

To go from mystery oil to synthetic all you have to do is just change the oil and filter. I used M1 in my Liberty for two years before I traded it in for my wrangler. I also use Lucas Full Synthetic Oil Stabilizer.

I am how ever about to switch to Royal Purple full synthetic from my next oil change. I would never from synth back to regular oil or even synthetic blend because there is NO reason to ever go back.
 
#10 ·
Let me know if you can see/feel any difference with RP Synthetic oil.
 
#12 ·
Go redo your oil change and put a full synthetic oil in. Maybe it's me but I like to take care of my baby girl. Kinda like ppl say you don't need higher octane gas well I use 87 just for sh**s and giggles. 10 cents more a gallon who Knows it could get u a thousand more miles in the end.

Basically wether u want to spend the extra few bucks on synthetic or you don't. You might as well cuz it's not for you it's for your jeep.
 
#14 · (Edited)
I'm not on the synthetic engine oil bandwagon.

Synthetic oil is good stuff and EXCELLENT for extremely cold weather conditions where it definitely works better than conventional engine oil. But in my temperate climate which even includes hot desert conditions, I stick with conventional engine oils like Valvoline. And conventional engine oils must not be too bad, I've yet to have a single engine or lubrication-related failure in 48 years of driving with nothing but conventional engine oils. My last TJ had over 191K miles on it when it was stolen last year and its engine ran as well as the day I bought it brand-new on nothing but conventional engine oil.

Today's conventional engine oils are nothing short of superb and except in extreme cold conditions like you'd see in North Dakota, Buffalo NY, etc. where even I would run a synthetic, they will protect your engine very well. And in my personal opinion, just as well as synthetic which so many have blindly pledged 100% allegiance to.

So what am I saying? That contrary to what some think or want others to think, today's conventional oil are superb and your engines will thrive on them. You DO NOT need synthetics to achieve long life from an engine, that is well proven by those like me who have never bought into the rumors that only synthetic lubricants can do that.

And a little known fact that only older guys like me may remember... back in the 50's when synthetic engine oils were not yet on the store shelves, Volvo and Mercedes Benz had a long-running series of advertisements showing their customer's engines making it past the million mile mark. And guess what, that was on conventional engine oils available back in the 50's. No, you don't need synthetic engine oil to insure your engine is well protected. Regular oil and filter changes is all that is needed.

To read what some synthetic oil enthusiasts claim, you'd think our engines would burn up and seize if you use anything but synthetic. :rofl:
 
#16 ·
From what I've always read and heard, switching isn't a problem but they always recommend that when you have a brand-new engine you should break it in with conventional oil for the first couple hundred miles or so. Then you're fine to switch to synthetic.

Me, I cast my lot with the Mobil1 crowd. Been using it for years in a number of vehicles and found it to be good stuff.
 
#17 ·
Jerry:
With all do respect your jeep majesty, I do not think my motor is going to go crash bang boom if I do not use Tiger Blood, I mean synthetic oil. I think my engine is going to fall prey to the boogie man just because it is mine.

I have had a deep seeded phobia that my vehicle is "about to break down around the very next bend, or after the next bump" since I was 16. The only way I can drive without this fear is if I don't own it or rented it.

So I do the best I can by vehicles. PLUS I was given a case of M1FS by a friend to apologize for not jumping into a bar fight with me (for the record, I blackened the other guys eye worse then I had ever seen blackened before) and I believe once you go to the dark side there is no going back so I stuck with it.

Now my next oil change will be Royal Purple. I will still be using Lucas Full Synth Stabilizer, unless Royal Purple makes their own FS OS.
 
#18 ·
A test of Lucas's Stabilizer by Bob is the Oil Man's site showed it actually degraded the oil's performance by allowing it to trap air which reduces its ability to lubricate. No good quality engine oil requires an aftermarket additive and quality oil manufacturers specifically recommend against adding additives which can disrupt the careful blend of additives they designed.
 
#28 ·
a test of lucas's stabilizer by bob is the oil man's site showed it actually degraded the oil's performance by allowing it to trap air which reduces its ability to lubricate. No good quality engine oil requires an aftermarket additive and quality oil manufacturers specifically recommend against adding additives which can disrupt the careful blend of additives they designed.
x10
 
#19 ·
just put mobil 1 into my 01 with 87k with a wix filter because ive always used synthetic in all my vehicles for the "better protection" they claim. i try and do what i can, i do not recommend putting stuff like seafoam into the oil on older vehicles with higher miles because i had a nissan pickup with 150k and not saying it was because of the seafoam but shortly thereafter i threw a rod is what im guessing happened sold it for 500 bucks and called it a day though haha
 
#22 ·
Jerry:
I was told to use Lucas OS by a friend I trust, but I may have just bought my last bottle ever.

Thank you!
 
#26 ·
I've read that going from Dino to synthetic causes rear seal issues. From what I've read here that statement is BS. Got my 60,000 service coming up. Since the guy I bought it from had no idea what oil was used I've wondered what oil to use. I'll give M1 a shot since there seems to be no leaking issue
 
#46 ·
I've heard that as well, but experienced the exact opposite. When i picked up my Jeep, used, it had a slow rear main leak. Maybe one drop every couple hours. I used conventional 10w30 for the first oil change to get a baseline, and so no change in the drip frequency. I switched to M1 synthetic 10w30 for the next change and the drip slowed down to one or two a day over the course of a couple weeks. 2 years later sticking with M1 synthetic and it'll leave a parking space dry for a week at a time.

I'm not saying that the switch definitely caused it; maybe a piece of crud broke off and gummed up the leak or something, but I'm happy not to have to do a rear main job now.
 
#27 ·
Dino oil to synthetic can cause leaking problems. The size of the oil molecule in synthetic oils is pretty much all the same, but with dino oils it is all over the board in size. Those larger molecules actually do good in blocking the small oil leak passages.
 
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