Swith to synthetic or not? Want good reasons.

[wright784]

I hope this question has not been answered in this forum a million times, but I want to know if I should make the switch to synthetic oil from dino oil.
My engine is a 1990 VW 1.6L diesel w/ 178K miles on it. I've heard it is a bad idea to switch to synthetic with high miles because of sludge buildup. However, I had my oil pan off of my car and the bottom of the engine, everything below the pistons was clean. I'm afraid to take off my valve cover and look inside the combustion chambers. I have never done that before and I would hate to mess up my engine.
I have heard switching to synthetic is a bad idea because all of the microscopic grooves in the metal will consume or hold oil causing "oil consumption". Would it not be a good thing that those microscopic grooves be filled with oil...to cause less wear?
I have been running Shell Rotella T 15w40 w/ 1 or 2 cups of Lucas HD Stabilizer. I thought the Lucas Oil will help prevent dry starts but 1 or 2 people railed on me for using it on VWvortex for using it, and called it snake oil. I guess I will only know for sure after I get a UOA with straight dino oil.
Has anyone ever had any problems switching to synthetic with high mileage?

 

[bmwtechguy]

I have seen some high mileage engines start to leak oil when switched over to synthetic oil. Just depends on the particular engine and the syn oil used. Was the oil always changed on time?- is one thing to look at. You said that the oil pan and bottom of the block looked clean. That sounds promising so far. A look at the top of the head may tell more about how clean the engine is.

If your engine has never been rebuilt, that means the seals and some of the gaskets have nearly 20 years on them plus lots of miles. That is another factor to weigh. If you do make the switch, you may want to go with one of the good Group III synthetics such as Rotella 5W-40, and go from there. This oil is not so expensive and may not be as likely to start leaking as one of the higher groups, since the base oil is more like the non-syn oil you have been using.

BTW, you didn't mention any reasons why you were considering the switch to synthetic. I'm not sure I understand the reason NOT to use synthetic that was given to you, and I've never quite heard that before. I do know that you can usually go longer on your oil change interval and have better cold starts and possibly better fuel economy when using synthetics.

I would have to second the notion to forget about the Lucas in your oil. Unless you have worn bearings and excessive clearances or oil consumption, the Lucas is really not going to do much good. I would much rather have some of the Schaeffers additive #132 moly, described here: http://schaefferoil.com/specialty/132.html
I believe you would get much more for your money.

You could also consider Auto-RX, described at length in many posts here on the oil additives forum and on their website of the same name. Both Schaeffers and Auto-RX are sponsors here as well. I use these two products and can say they both are worth the money.

 

[Doug Hillary]

Hi,
wright784 - IMHO you would be well advised to stay with the excellent product you are already using - Shell's Retella T 15w40

I would NOT use any supplementary additives - they are NOT required

 

[lazaro]

there is people who use synthetic oils and have great results and never look back.
and there is people who try synthetics and dont get instant results and go off the deep end.
if you decide to use synthetic oil, you will be doing yourself and everyone around you a favor.
less time spent under the car, less money spent at the end of the year, less waste oil, it is a no brainer for some people.
I havn't done a 3000 mile oil change in 10 years. with 5 vehicles that I maintain that is a few 55 gallon drums of waste oil I didn't have to fool around with.
I could go on for days on the benefits.......

 

[Volvohead]

I'd stick with the Rotella, and perhaps ARX it. Dump the Lucas. If it gets too cold in the winter, try RTS.

You'll go at least another 578k with it, and the waste oil keeps the mechanics toasty warm in the winter.

 

[Bill Plock]

I second Doug's and the other's excellent advice .. stick with the Rotella 15w40 HDEO or similar product like Chevron DELO 400. I had an 85 VW 1.6 Golf diesel that I bought new .. sold it in 2001 with 180K and it was sill running like new (I now regret selling it ..it was the best car I ever owned) I ran 15w40 HDEO's with it and it always started with no problems in the cold North East Winters .. last I knew it was still going strong for the current owner. It would load the oil with soot fairly quickly so I changed the oil every 2-3kmi... I would also recommend you change the fuel filter regularly and use a fuel lubricity additive (i.e. Stanadyne and/or TCW3 2-cycle oil)