Switch to Synthetic Oil?

[EricT]

Why do you hate their marketing campain, or is their oil really that inferior???

from seeing what it has done to engines that I have taken apart in the past, my dad use to swear by it till we tore into his 914 engine for a rebuild, switched to castrol and have not see the same problems

I used to use mobil 1 in all my vehicles. One time I did an experiment with amsoil in my track car, with mobil 1 and a 1 qt larger oil pan, I was seeing oil temps peaking at 267 degrees. I switched to Amsoil on even a hotter day at the track and my temps were back down to 237 peak. The amsoil disipated the heat better, so I have been a believer since.

 

[GhostDakota]

I'm running Mobil 1 Synthetic on my '91... the engine is a '93 with roughly 59k miles on it. I was leaking very slightly from my rear main seal, and I am still leaking slightly from it. Nothing more than before. I changed the oil about 5k miles ago and I just added one quart to it. No big deal. My old YJ used to suck up 1 quart a WEEK on regular oil!

Also, what do you all think of Amsoil/Royal Purple?

Edit: I see the thoughts on Amsoil lol.. From what I have heard, it's the same thing about it being a GREAT motor oil.

 

[GhostDakota]

This may not matter, but I've seen numerous Used Oil Analyses on the 4.0 and Mobil 1 10W30 has shown elevated iron wear rates.
I know many say "Well, I've run Mobil 1 10W30 for XXX,XXX miles and no problem."
But without doing a UOA, you don't know how well your drivetrain is being protected, or how many more XXX,XXX miles you could get with an oil that has better metal wear rates.
If anybody wants a look, I have loads of data on this engine, using various brands, and viscosities.

I would love to see it! Do you have data from Mobil 1 Synthetic, Royal Purple and Amsoil? Thank you!

 

[bewilderedbeast]

I would love to see it! Do you have data from Mobil 1 Synthetic, Royal Purple and Amsoil? Thank you!

PM me with an email address and I'll send you the file. So far, I have 20 samples, and there is indeed an Amsoil 5W40 thereas well as several Mobil 1. I haven't copied all the UOA's available yet, but this is a start.

 

[Root Moose]

PM me with an email address and I'll send you the file. So far, I have 20 samples, and there is indeed an Amsoil 5W40 thereas well as several Mobil 1. I haven't copied all the UOA's available yet, but this is a start.

I have the spreadsheet and will post as PDF some time this PM - if the weather holds - satellite is winking out and I have work that needs to be done when it is "up".

Hold that thought...

 

[Root Moose]

Ok, dish is green for longer than 30 seconds... But the rain is coming down harder...

Here's the PDF:

Oil_comp_Analysis.xls.pdf

 

[GhostDakota]

Ok, dish is green for longer than 30 seconds... But the rain is coming down harder...

Here's the PDF:

Oil_comp_Analysis.xls.pdf

Thanks much! Is this the same thing that was stated before?

 

[Big Red]

Thanks Root Moose for the data. What conclusions can be made from them? What's the best oil? Can a Dino oil compare to a synthetic.

 

[GhostDakota]

The charts are kind of confusing to me? I see the Viscosity, etc., but not sure which numbers are which oils, what the Fe wear means, etc. What order are they in from best to worst?

 

[Comanchedude]

Mobil one is not a true synthetic oil it is dino based oil ,

I would like you to prove that statment, as it is WRONG

 

[bewilderedbeast]

It is indeed wrong. Mobil 1 is a Group IV synthetic.
Group III is a severely hydrocracked dino oil.(Rotella T-Syn, Castrol Syntec, maybe Pennzoil Platinum).
Doesn't really matter, does it? Aren't results what count?

 

[ltkaknm]

So in summation is there a concensus on whether going to Synthetic is a good thing? I have a 90 XJ 4.0 L and I have been using the SUV mix with Lucas Oil Stabilizer but I am thinking of switching to Mobil 1. I use the high end Mobil 1 filter and it seems to work well.

I do have some oil leaks and I would be interested to see if switching to synthetics would help or hurt.

Any advice would be appreciated

LTK

 

[SCW]

I don't think there really is a concensus. this is just a big internet commitee, nothing is ever decided on.

I tried a synthetic blend and ended up changing the rear main, filter O-rings and valve cover gasket before it quit leaking. If your prepared for that possibility, try it out.

 

[bewilderedbeast]

I think that if you're changing at 3000-5000 miles, it's a waste of money to buy a synthetic, since for short intervals there's not much difference in wear rates.
If something gets "cleaned" by a synthetic oil, or a cleaner like Auto-RX, it's something that shouldn't be there anyway. Just my opinion.

 

[Big Red]

I think that if you're changing at 3000-5000 miles, it's a waste of money to buy a synthetic, since for short intervals there's not much difference in wear rates.
If something gets "cleaned" by a synthetic oil, or a cleaner like Auto-RX, it's something that shouldn't be there anyway. Just my opinion.

True both those natural oil leak plugger Dino oil residue are nice. Kind of sucks when your Jeep starts leaking like crazy when you go to synthetic.

 

[bewilderedbeast]

Yep, but if it's been kept fairly clean, it won't.

 

[EricT]

The charts are kind of confusing to me? I see the Viscosity, etc., but not sure which numbers are which oils, what the Fe wear means, etc. What order are they in from best to worst?

Fe wear is probably the amount of iron in the oil, but like you, I don't know how the numbers are labeled.

 

[ddeadserious]

I did one oil change with synthetic and it made a massive leak(at least 1qt/day) until about 3 days later where i did another change using non-synthetic 20W50. It still leaks wayyyyy more than before the synthetic switch.

 

[rescuejeeper]

I started using full synthetic oil in my '95 XJ about 5 years ago. I swear by the stuff, and would never go back to regular oil. I use full synthetic oil in all 3 of my jeeps, it can be expensive but well worth the price.

As far as a leak, I did have one in my '95 but that was a loose valve cover gasket.

 

[mikeny59]

Full synthetic switchover at 3k miles back in '98, 116k now, engine idles and pulls better than new, I still change oil/filter at frequent intervals, less stress than a motor rebuild in the long run is my philosphy; just cut some financial corners elsewhere to afford it :rattle:

Btw, this includes the aw4, I must be one of those lucky exceptions, even w/3.55's and 31's and pita shifting in and out of od manually all the time, no sign of odd behaviors or slippage, etc...

Includes religious screen changes/cleaning and not stompin' on it.

All Mobil1.