Fully Synthetic Oil - BMW Forum

loud068 · 07-06-2005, 08:53 PM

I read an article the other day that said that using fully synthetic oil on a car that has high mileage is good for the engine. Is this true, because I have always been told that as long as you change the oil every three thousand miles it is not necessary to use fully senthetic oil.

Bear · 07-06-2005, 09:10 PM

Fully synthetic has the advantage of not being petroleum based so no sludge build up. However, if you change your oil and filter every 3000 miles using standrd petroleum based oil, you should not have a problem. Synthetics can also go longer distances between changes (I changed the oil in my 1988 750 every year or 15,000 miles whichever came first, but also changed the filter every 5,000 miles).

Furious · 07-07-2005, 01:21 AM

wasnt there something said about if you change to synthetic very late in the life of you engine, than it may actually have a bit of a negative effect.... anyone wanna clear that up?

93 325i · 07-07-2005, 07:47 AM

You will most likely develop leaks if you switched to fully synthetic. The synthetic oil will break down all the old oil deposits around the gaskets that have built up over the years and create leaks. So in turn it is cleaning out the engine, but also breaking down the previous deposits that helped seal the gaskets. If your engine is in great condition then you may be able to sneak by with little to no leakage. I am doing a gradual switch from sythetic blend to test and then eventually to full. I started the switch with 130K miles and am now up to 137500 and have had no issues of oil loss, consumption, or leakage. So next change im going over to full mobil 1.

Rookie · 07-07-2005, 12:57 PM

I started running full synthetic at 68,000 miles and am now at 74,000 miles and I don't have any leaks at all. Just if you are going to pop the extra cash for synthetic then for christ sake buy Mobil 1 it is the purest and the best choice!

RexKing86 · 07-07-2005, 01:06 PM

I use Mobil 1 also. I ussually change my oil 3 times a year, but check my oil level frequently. Ive only had the car for about 6 months and i just did my second mobil 1 oil change. Ive had no problems so far. I have heard once that once you go to synthetic, you cant go back to regular oil... doesn anyone know if this is true?? (not that I plan on going back anyway...)

Bear · 07-07-2005, 03:18 PM

All cars are different, and on my '88 750 I started using full synthetic at 96,000 miles. Now at 140, 000 miles I use no oil and have no leaks. There is no problem switching back and forth from synthetic to petroleum based oil

aheath · 07-07-2005, 03:31 PM

Quote:

Originally posted by Bear@Jul 7 2005, 03:18 PM
Now at 140, 000 miles I use no oil and have no leaks.

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It would be hard to have any leaks if you use no oil.

drz · 07-07-2005, 04:12 PM

I switched to Synthetic on my 328i at around 170,000 miles. I use Mobil1 5w30. I have not detected any leaks. I have changed the oil twice since. I got luck about having no leaks. I did the switch even though it is late in the engine's life because I'd rather have an oil leak or two as a side effect of getting all the benefits of synthetic. I don't want any mineral-based "gunk" swimming around inside my engine.

loud068 · 07-08-2005, 03:33 PM

First off mobile 1 and castrol syntec are not fully synthetic, they poth have synthetic properties however they are not fully synthetic. The only two true synthetic oils are amsoil and redline.

drz · 07-08-2005, 03:42 PM

There is a fully synthetic Mobil1 that came out recently.

Rookie · 07-12-2005, 10:33 AM

I wonder if bears engine is still running even though he feels special enough to not have to use oil

cloaked95 · 07-12-2005, 07:23 PM

Quote:

Originally posted by drz328i@Jul 7 2005, 03:12 PM
I switched to Synthetic on my 328i at around 170,000 miles. I use Mobil1 5w30. I have not detected any leaks. I have changed the oil twice since. I got luck about having no leaks. I did the switch even though it is late in the engine's life because I'd rather have an oil leak or two as a side effect of getting all the benefits of synthetic. I don't want any mineral-based "gunk" swimming around inside my engine.

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Isnt 5w30 too thin for BMW?

thekid · 07-12-2005, 11:56 PM

Mobile 1 does have a full synthetic out. But read carefully to make sure you are getting the full synthetic.

Also there is no rule saying that you will develop leaks when switching to full synthetic. However, it does happen. It is better to use full synthetic. Just judge the risks vs. the benefits before you make the switch.

Angelic0- · 07-13-2005, 01:30 AM

Anyone out there heard of Militec ?

It's a stuff us Icelanders developed for rally-cars, and we use it as "add-on" to all of our oils, including gear&drive oils

I could post a pic of a bottle, and just contact me if you wan't this stuff