Why Go Synthetic?

[monst]

Me again,
  I was wondering.... Why go synthetic?..
on motor oil.....(particularly AMSOIL).
I was gonna run 10W 30.. afraid to
go too thin (5-30).... 140K on 91 Jetta 1.6l(NA).
It appears that she is tight.... not leaking
as far as I know....  Cleaned her up and
she is remaining clean and fixed the know leaks.
I had heard that
(well this could just be old info)
that it is better to not go from regular oil to synthetic....
another note: I had the valve cover off... motor is
very clean........
thanks monst :?:

[jtanguay]

i would never go with 10w30 unless it was an emergency and the temps were around -25 or so, and it was a blend.  5w30 is out of the question.

go with a good synthetic 15w40.  I have even considered going with 20w50 for the hot summers.  Don't think my car would need it though.

if you go with dino oil, use shell rotella T.  if you go synthetic, any of them should do, but obviously some are better than others.

I would recommend synthetic for sure.  Better mileage, turbo spool up, and less worry about having to let the turbo cool down so much (synthetic does not coke as bad as dino) and you can rest assured that on cold days the oil will flow to where it is needed quite rapidly, since synthetics have lower cold pour temps.  Add in the fact that there are better detergents, and TBN number, you can extend oil change intervals to around 10'000km (i'd say that is max on a diesel, since the dirty soot needs to be cleaned)

[RAMMSTEIN]

I run 0W40 full synthetic in both my 1.6D and my TDI with no problem whatsoever.

10000km oil change?

Way too early.

I do mine every 20 000 with good feedback from oil analysis.

If the oil is good after 20 000 km with the TDI (which has EGR and Turbo), it will be fine with the 1.6D NA.

Rotella T 0W40 is full synthetic, at least it's what is says on the jug.

The '0' is a cold viscosity index and the '40' is the hot viscosity index. All you really need is oil that can support heat.

[monst]

So there are good points all around. to go synth...
I had never heard of 0W 40....  How are the
cold pumping pressures. It flows good
Would you say the pressures are more stable
than with a 10 30 or a 15 40..................
I end up with high starting pressures and
like 20 psi(at idle when it is hot)...
What about a Filter?

[RAMMSTEIN]

I use OEM filter (no purolator or fram crap) and never had any problem.

The 0W40 is excellent in winter, it stays liquid even at -1000. :wink:

As for pressure, I don't have an oil pressure gauge in any of my cars.

[saurkraut]

First and foremost, i am no oil expert.  That being said heed the following:

Keep an eye on the API rating.  I havn't seen a 20w50 with a C rating in a long while.

Remember: C= compression ignition, S = Spark ingnition.

The "C" rated oils have detergents to break down the soot that diesels put in their oils.  With out this ditergent, the soot paricles will eat your bearings and bores.

Along time ago, I had a naturally aspirated diesel that i fed a steady diet of Castrol 20w50.  When I started doing this, it was CD rated.  Years later, when i was doing a head gasket, I pulled a piston.  The bores were visably worn, and the rod bearings were showing copper.  I looked again at the Castrol 20w50 bottle, and the "C" rating was gone.

Right now in the states, I'm only aware of 15w40 and 10w30 dino oils that have a "C" rating.  The synthetics are all 5w40.  I think the current "C" rating is CI-4.

Any thing else does not belong in your diesel engine.

[monst]

C- rating for compression ingition engines....
The idea is detergent to break down the soot.....
After it is broken down(that being the soot)...
Then what? it is retained in the oil filter better.....
Just curious. Are there oil filters geared towards
accomdating this environment better. I know the
fram filters are bad.... when they lose their filtering
ability cause of dirt they become (non-filtered)
like a Lucky Strike cigarret butt.... Aparently they
have like a blow off (pressure relief valve) in them...
and the filter element is by passed.........

[saurkraut]

The soot stays in suspension.

Use the VW oem filter, it has no baypass.

Drain interval:

My personnel observation on running synthetic.  the engine in question is a 85 1.6td bored to the first oversize, with new pistons, rings bearings ect.  probably 80K miles.  Grossly over fueled and boosted.

Broke in on dino oil, switched to synthetic after that (Rotella or Delvac 1).  Ever since, I can get about 2,500 miles on a pan of oil, and it doesn't use any.  After 2,500 miles, it starts to use oil, typically a half quart in the next 500.  Whats happening?  I'll venture a guess.  The oil can no longer break down the soot, and the soot particles are lifting the piston rings.

Change oil, and every things OK until 2,500 miles.

Perhaps the TDis are a little kinder to their oils, but these IDI motors are a little messier, especially if you drive it like you stoll it.

[monst]

Cool... I am going synthetic.....
I stumbled upon some nice reading......
http://en.wikipedia.org/wiki/Motor_oil#Use_of_motor_oil
It highlights all that has been provided on the posts here....
Thanks for the info........
  Check the link out...... some of the info is excruciatingly
obvious.... but in all there is some good detail... and some
links to more info at the bottom of the page.
Thanks, going synth this weekend. :lol:

[RAMMSTEIN]

Right now in the states, I'm only aware of 15w40 and 10w30 dino oils that have a "C" rating.  The synthetics are all 5w40.  I think the current "C" rating is CI-4.

Any thing else does not belong in your diesel engine.

All synthetic are not 5W40.

You can get 0W30, 0W40, 5W30, 5W40, 10W40 and 15W40 either from Amsoil, Esso (Mobil here in Canada for some product), Elf, Motul (and the list go on and on) synthetic oils.

Most of these oil are available with a C rating.

Monst, where is pst?

Pacific Standard Time? :lol:  :wink:

[jtanguay]

full synthetic isn't 100% synthetic though, just remember that.  The only reason I would say 10'000km is because you can suspend the carbon in the oil, but eventually your filter gets plugged up.  I guess if you just changed your filter you'd be ok, or depending on how expensive the oil is, you could extend to 20'000km.  And yeah, dont go with fram.  I've used them but have smartened up and went back with the Bosch.  I mean come on, if you're really worried about a plugged filter, your engine oil light will come on and will signal you that you have low pressure, and boy you better change that oil asap!!!  :lol:

I found a really neat product from a company that actually mixes some of your used oil with the diesel fuel to burn it, and then replaces that oil with fresh oil into the oil system.  Pretty expensive, but would be great on our old diesels.  

yes our old IDI's with super high compression have a tendency to get dirty oil fairly quickly, especially if we like to drive it hard (how can you not though???).  Pressure from the cylinder shoots past the rings, and into the oil (including soot particles)

I just recently bought a jetta (parts car).  The guy had his turbo feed line rust out, and he drove it like that for a few days before he realized it had happened.  So he buys a new line and installs it.  Week later his car starts getting harder and harder to start until he cant start it anymore.  Guess what happened?  His new oil line basically flushed all the coked oil, and soot and whatever else gunk got cooked by a starved turbo.   All into the oil pan.   My best guess is that the coked oil particles started machining critical engine parts.   It will make for a good rebuild I think .  I think if he had a good synthetic motor oil in the car, he might have avoided it, but I would not have had such a decent deal.  

about the 20w50...  I was always considering using that oil in my car.   Never checked the bottle though  but would have if i ever considered doing it.   Didn't know that it didn't have the compression ignition api rating.  Must be some out there with it though... would be great if you could get a synthetic 20w50 that was easy to start in winter... would be a nice oil for older diesels. (maybe quiet them down a bit too)

[RAMMSTEIN]

Jtanguay, 20W50 will never be easy to start in winter (even if synthetic) because it starts by 20....cold viscosity index remember... :wink:

If you go to Wallmart, you can pick up some Esso XD-3 0W40 for 25$ tax in (4L jug).

It's full synthetic and it does wonders in winter.

Or go to Crappy tires and get some Rotella T 0W40.

[saurkraut]

Rammstein,

I'll have to point out that the USA is behind Canada in the Diesel world.

Down here, the only synthetic "C" rated oil is 5w40.  The caviate being available through normal commercial venues.

Amsoil has a merriad of oils with a merriad of "certifications".  And I'm not too keen on using an oil that must be shook be for using, or a cloak and dagger order and delivery system.  

For instance down here, Wallmart occasionally carries the Rotella 5W40 synthic diesel oil.  I say occasionally because I have gone there looking for it because I'm comming up on oil change time, and it is out of stock and on tripple back order.  There is no 0W40, 0W30 or 0Wanything that is "c" rated down here at Walmart.

Delvac 1 is available down here in a 5W40 at Fleet Farm, relabled as truck & SUV oil, or some gibberish of that sort.

So yes, there may be allot of choices up in Canada for "C" rated oils, and I applaud Canada for that.

Down here, the pickens are pritty slim, but Rotella's and Mobil's offerings are good in thier own right.

Best regards

[jtanguay]

true that 20w50 will start at a 20 weight, but then again synthetics don't thicken up as much.  With a dino 20w50 oil, I would be scared.  Synthetics on the other hand, they flow quite easily, right down to -50C or so.

Some caution would need to be in place when starting in winter, such as letting the oil circulate before having some fun etc.  I'd guess that 1-2 minutes idle time should do the trick.

It is my opinion that synthetic 20w50 flows like dino 15w40

[macsdub]

i wonder if this thing would work on our cars??
they make claims like "honey colored oil after 4000miles" and stuff
wonder if its any good???

http://www.fs2500.com/