Synthetic or non-synthetic engine oil?
- Thread starter CSL 1973
- Start date
Tyler
Well-Known Member
I'm using Valvoline VR-1 20w50 non-synthetic, which I believe is the spec weight for the M30.
10w60 may be too light - its formulated for modern high tolerence engines - I believe it was made especially for the E39 M5.
10w60 may be too light - its formulated for modern high tolerence engines - I believe it was made especially for the E39 M5.
MichaelP
Well-Known Member
If you have have a glovebox owner's manual, you'll see that BMW recommends 20w50 for warm weather and 10w40 for cold weather. Even as late as 1988, when synthetics were available and BMW was recommending their use in the S14 and S38, non-synthetics were still recommended by BMW for M30 motors. I recently sold our 1988 535i (M30b34) with 400,000 miles on the original motor. It got non-synthetic every 3 to 5K miles (Castrol, Valvoline, Pennzoil) and it was ready to do another 100,000. The head was never removed from the block, and although there was a little piston slap (worn wrists, I think) when it was cold, the cams looked fine.
If you crank a cold motor over in cold weather with something as heavy as 10w60, you'll get very little compression and likely damage your motor in short order.
If you crank a cold motor over in cold weather with something as heavy as 10w60, you'll get very little compression and likely damage your motor in short order.
Thanks for the advise. It sounds like Valvoline VR-1 20W50 could be very suitable. I have also been recomended to use "Castrol GTX High mileage 15W40", which should be specially made for older engines. Opinions/experiences about that Castrol oil?
MichaelP
Well-Known Member
There's no better way to get a forum war heated up than over motor oil, but here's my 2 cents: according Valvoline, VR-1 is made with detergents for high RPM motors that suffer wear and oil foaming due to high heat stress. That doesn't sound like my M30s, so I stick to conventional oils. "High-mileage" oils contain detergents that avoid sludge buildup, seal oxidation and oil burn off. My attitude is that if you change your oil often enough, those additives aren't necessary. If you have oil burn off, you have ring problems that motor oil won't fix.
chicane
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CSL 1973 said:
TWS might be overkill for you CSL, I would just go with Mobile 1. It is required for my e46 M3. It sure can't hurt it is very good oil (and expensive about $10-12 a liter). One thing if you decide to stick with TWS, it is very thick and there is actually a warm up procedure with the ///M. You aren't suppose to go over 3000 RPM until you reach operating temperature and one reason is because of the thickness of TWS.
jhjacobs
Well-Known Member
Interesting thread. I've alway run Mobile 1 in everything but my coupe. Synthrethic oil is hands down better than conventional in most respects. However, regularly changed convention oil is also good - just never go over 1 year / 5000 miles on a change.
However, when Mobil 1 hit the market in the late 70's I remember hearing that it would damage seals on older engines and it is more prone to leak from old gaskets. I have seen anecdotal evidence of this (seals and gaskets may have been ready to go anyway) but I find it hard to believe. Doe anyone know the real scoop on this? Are Mobil 1 and other synthetics seal and gasket friendly?
However, when Mobil 1 hit the market in the late 70's I remember hearing that it would damage seals on older engines and it is more prone to leak from old gaskets. I have seen anecdotal evidence of this (seals and gaskets may have been ready to go anyway) but I find it hard to believe. Doe anyone know the real scoop on this? Are Mobil 1 and other synthetics seal and gasket friendly?
jhjacobs said:
My understanding is that its all about the molecules. Synthetics lubricate better because of its molecular makeup, which allows it to get into places that conventional oils can't. I don't know anything about it harming gaskets and seals, but it may look like it does since it can leak though existing areas that conventional oils don't.
Dan
Malc
Well-Known Member
my 2 pence worth is that old design engines are very happy on good old (and cheaper) 20/50, GTX and alike as they were designed around the lubricates of the day. THus a coupe engine on a diet of 20/50 is very happy!
Synthetics are great for modern engines built to finer tolarences (spelling) and are recommended by today's manufactures
Synthetics are "thinner" thus worn engines and old seals will leak more than the "thicker" old stuff again tolarences play a part here.
Driving style and conditions
Lots of town driving, short runs versus motorway, long distance stuff effects the life of oils.
In the case of the former change the oil and filter every 5000 miles or twice a year, which every occurs first, in the case of the latter every 10,000 or once a year is fine.
Malc
Synthetics are great for modern engines built to finer tolarences (spelling) and are recommended by today's manufactures
Synthetics are "thinner" thus worn engines and old seals will leak more than the "thicker" old stuff again tolarences play a part here.
Driving style and conditions
Lots of town driving, short runs versus motorway, long distance stuff effects the life of oils.
In the case of the former change the oil and filter every 5000 miles or twice a year, which every occurs first, in the case of the latter every 10,000 or once a year is fine.
Malc