Synthetics worth it?

[sle2115]

While not in diesel engines, I prolly have 8 or 900,000 miles on synthetic. On a new vehicle, I like to get at least 5,000 on them or so to allow for break in.

I made my choice when working on state patrol vehicles in the machine shop, where they did 100,000 overhaul intervals. We saw engines with 3 or 400,000 miles on them with next to no wear and VERY clean internals. The overhauls were not needed, but required as was the use of synthetic oils by the department. To be honest, I have seen them that ran Mobil 1, Syntec, Amsoil, Quaker State, or a mix of them all, etc., just depended on the drivers choice as they are required to maintain their vehicle. Engines had very few deposits and as I said, no wear. We never bored an engine or turned a crank that I can remember, and I was the one who did the work on them, they were pretty much under my control from the time the entered the shop till they left. We generally could do a hone on the cylinders, polish the crank, valvejob (which was hardly ever required), clean the surfaces and bolt it back together! We did see a few diesel engines on synthetic though and they were pretty much consistant with the gassers.

 

[rubberfish]

Dino oil for me. And change it regularly.
Not interested in syn for a motor
that's going to go boom regardless.

 

[cdennyb]

when did I switch the engine over?

Well, without looking at the maint book for the exact number it was around 26,000 to 28,000 and before that I switched the trans and rearend.

I've always used the silver jug of diesel service fuel additive and it makes for a good mpg...especially the more you drive it. Now that I'm into the 110,000+ mile range I've noticed it runs smoother and cleaner and certainly gets the good mileage.

db

 

[gumper]

340,000 was my switch to HDD 3000 AMSOIL with their high filtration filter. Never too late to switch over. Yes, it'll eventually be worn out. But might as well get 700,000 miles or more out of it huh? Synthetics have been proven to make things last longer. There's just a few sticklers who'll never change their ways.

 

[Locomotion]

When I switched over to Amsoil in my '92 Dodge, I saw lower operating temps and slightly better fuel mileage. Less heat means less friction, which means less wear, more HP and better mileage! Stretch out the change intervals, confirm the condition of the oil by sending samples off for analysis, and you could save some money.

My engine builder says he's seen less wear in synthetic oil race engines on a regular basis.

Amsoil source & info page:
www.thelubepage.com

 

[wilsondoctor]

Here we go again;
Used systhetics in the past - no real gain in drain intervals - oil analysis said to drain @ 7000 - switched to Lubrication Engineers products - analysis determined to drain @ 14000.
Thanks
JL

 

[lpennock]

Here we go again;
Used systhetics in the past - no real gain in drain intervals - oil analysis said to drain @ 7000 - switched to Lubrication Engineers products - analysis determined to drain @ 14000.
Thanks
JL

Sounds like a 2x improvement to me. I've seen Royal Purple show lower wear particles in it at 21k miles than regular oil had at 3K miles based on oil analysis.

 

[wilsondoctor]

Royal Purple

YA. I used to run Royal Purple in my running gear and LE in engine, switched to LE in all components. All great stuff. I could never understand hard working , smart people putting the cheapest stuff in there multi thousand dollar trucks. Engine oil analysis only cost $16; great insurance. Actually tells you want is going on and the best product for your truck - without just taking someone's else's word for it.
Thanks
JL

 

[Heiseroil]

I've run Amsoil in my Dodge ince about 20k miles. I don't run a bypass filter, but plan to add one soon. I ran my last batch of Amsoil HD Diesel and Marine motor oil, along with the Amsoil oil filter in the stock location, a total of 25k miles before changing. I did Oil analysis about every 5k miles, and everything checked out fine at 25k, and the oil could have gone longer. I changed it just because, really..
Scott

 

[WrickM]

When I switched to syn oils (on passed vehicles) I noticed the smell of hot oil but did not have acutal leaks that was until my current (Cummins) and it started leaking - but only when the outside temps were low - but this year I'm not seeing that - now I got to thinking the other day about what has changed - well the biggest thing is I have been running syn oils now for quite a while and I have been told that before I started using syns for the first time that seepage was normal when first out of the gate because the syn oils will have to swell the seals because the molecules were smaller and could sneak past the seals easier. Don't know if that is my case this time but it seems to be following suit... basically it's the only thing that makes logical sense.

It's not a molecule size issue, and if you really think about the difference in size of molecules affecting a seepage through a rubber seal it doesn't make a lot of sense It has to do with the lower viscosity specifically on startup. Almost everything in the engine swells with heat and when you start you engine cold with the lower viscosity of synths you may get some seepage because the seals haven't expanded yet. As the synth saturates seal it then becomes less of an issue.

 

[lpennock]

It's not a molecule size issue, and if you really think about the difference in size of molecules affecting a seepage through a rubber seal it doesn't make a lot of sense It has to do with the lower viscosity specifically on startup. Almost everything in the engine swells with heat and when you start you engine cold with the lower viscosity of synths you may get some seepage because the seals haven't expanded yet. As the synth saturates seal it then becomes less of an issue.

Also don't forget that Synthetic oils tend to be higher detergent so they tend to clean the sludge off the seals that were hold them from leaking before.

 

[lightemup]

I switched @ 15,000miles! Went with rotella synthetic for two intervals. Had no issues! Just went with mobile 1 & the Lucas oil stabilizer @55,000 miles. 05 cummins2500 good sale on the mobile 1! So far so good!

 

[GWDriver]

FWIW...........

Since I'm in the market for my diesel truck at this time, I can only go with my experience in my 352,000+ '88 Suburban. Original engine as far as I know. I started using Amsoil at 120,000k miles, using a dual filtration system the P.O. had put on. While I do change the oil more often than necessary, I lay the blame for the engine's mileage on being a fanatic for preventive maintenance while working on aircraft for over 20 years. I do have a bit of leaking in one seal, but it's no more than the leaking that was there when I used Castrol's dead dinosaur oil.