What oil do you use?

[studawg]

I read in the e30 BMW owners manual that BMW specifically states to avoid using full synthetic oils in the car and to only use natural or synthetic blends, and the recommended weight is 15w50 but if your in colder climates 10w40 is in range

Can you tell me where it says that about synthetic? I cant find it in my owners manual anywhere.

[studawg]

In SC, you can run 15W50 all year round. Be careful about going synthetic. Some users have seen big time oil leaks after switching over to synthetic.

Previous owner ran BMW synthetic for the last 60k.

[Cabriolet]

Can you tell me where it says that about synthetic? I cant find it in my owners manual anywhere.

usually it will causing your car to leak from every gasket/seal. if not leak i know for a fact that it will seep. i ran it for a while in 2 rebuild motors and they leaked from the seals until i went back to non-syn

[mpowerful]

Mine doesnt seep or leak with synthetic. 131k miles.

[studawg]

usually it will causing your car to leak from every gasket/seal. if not leak i know for a fact that it will seep. i ran it for a while in 2 rebuild motors and they leaked from the seals until i went back to non-syn

yeah yeah yeah, i know thats what some people say can happen, but I wanted to know where it says in the owners manual NOT to use synthetic. But, it does not say that.

I dont care if my engine leaks oil anyway. I want the best protection that I can get, and that most definitely comes from synthetic.

[studawg]

oils are a compromise as to what temp and operating conditions they provide their best protection. Since most wear is upon start up and warmup an oil that flows a bit better when at low temp is surely helpful at keeping all the bits apart.

there is no correlation between low ZDDP and synthetic.......

everyone should read through all the chapters here

http://www.bobistheoilguy.com/motor-oil-101/

apparently for a given viscosity say 10W-40 the syntheitc will flow better when cold than the mineral 10W-40

Wow, that link is very informative. I have been on bitog.com but had not read through that before. It basically told me everything I thought I knew was wrong, except that I knew not to switch between brands of oil.

After reading that, I think Im going to the M1 0W-40. the 15w-50 is just too thick, and the Castrol GTX 20w-50 mineral oil I put in there recently is WAY too thick. He doesnt recommend any conventional 20w-50, in any car, in any climate, for any reason.

I may run the T6 5w-40 since thats what I run in my 7.3 diesel, but I run M1 0w40 in the 540, so its gonna be one of the two....

Synthetic is most definitely the way to go, though. I already knew that though...:D

[Cabriolet]

yeah yeah yeah, i know thats what some people say can happen, but I wanted to know where it says in the owners manual NOT to use synthetic. But, it does not say that.

I dont care if my engine leaks oil anyway. I want the best protection that I can get, and that most definitely comes from synthetic.

the tldr is get Mobil One 15w50. it's proven

[studawg]

How do you know they used 15w-50 in that test?

[Cabriolet]

How do you know they used 15w-50 in that test?

someone never read their owner's manual

[studawg]

Wow, I feel like Im in the twilight zone. I have read the owners manual. How does your last post have anything to do with what we are talking about? I ask again, how do you know which oil M1 used in that test? Because they didnt say 15w50 in the video. Regardless, the only thing that test REALLY proves is that 99% of wear happens at start-up, of which there were very few in that test.

[pantelones]

everyone should read through all the chapters here

My bad digger...

Did a little bit of searching and yes you do have a good point. Found this...

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=98729&page=1

Didn't really find anything about fuel contaminates, but that is easy enough to understand. I did find this article though; it painted a good picture as to how some of the additives work to protect the engine.

http://www.machinerylubrication.com/Read/518/motor-oils

Another factor in fuel economy is temporary polymer shear. These polymers are additives known as viscosity index improvers (or modifiers). Polymers are plastics dissolved in oil to provide multiviscosity characteristics. Just as some plastics are tougher, more brittle or more heat-resistant than others, different polymers have different characteristics.
Polymers are huge molecules with many branches. As they are heated, they uncoil and spread out. The branches entangle with those of other polymer molecules and trap and control many tiny oil molecules. Therefore, a relatively small amount of polymer can have a huge effect on oil viscosity.
As oil is forced between a bearing and journal, many polymers have a tendency to align with each other, somewhat like nesting spoons. When this happens, viscosity drops. Then when the oil progresses through the bearing, the polymer molecules entangle again and viscosity returns to normal. This phenomenon is referred to as temporary shear.

someone never read their owner's manual

Hahaha, I though this was kind of funny...

Those charts are based on oil formulas from 20+ years ago. They are fairly meaningless when a modern synthetic 15w50 will outperform a 10w30 from 1986 in any condition for twice as long.

The fact is a synthetic 15w50 flows far better cold and protects just as well (if not better) hot as a 20w50 mineral oil. M1 15w50 also happens to have plenty of zddp and i can get it in a cheap jug at walmart.

QFT

[digger]

My bad digger...

Did a little bit of searching and yes you do have a good point. Found this...

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=98729&page=1

Didn't really find anything about fuel contaminates, but that is easy enough to understand. I did find this article though; it painted a good picture as to how some of the additives work to protect the engine.

http://www.machinerylubrication.com/Read/518/motor-oils

fuel contamination is of concern if the FPR is faulty


Hahaha, I though this was kind of funny...

QFT

also with an aftermarket ECU setting up the cold start and warmup maps can put more fuel into the cylinders than what the factory ECU does. especially if your start up map doesnt have these in the right ballpark and you are experimenting to see what works

[bmwstudent]

Kendall GT-1 20w-50, Frank Fahey recommended this to me years ago and I use it every time. High Zinc content and when it's on sale I stock up.

[SFF]

$22.00 for 5 quarts of Mobil 1 15w-50 at my local wal-mart(s) my m20 was happier than a pig in shit when changed the oil with this never again will i stray away from this brand and weight of oil again, as long as i own an e30

I honestly feel that 15-50 is the perfect weight and mobil 1 is the perfect brand, for our e30's but this is obviously just my opinion. then put some mt-90 in your tranny and your e30 pretty much has an orgasm

I agree on the 15W-50, I put it in my 88 325 and it felt better immediately. I will continue using this as it seems to be great for the Nor Cal climate. I'm watching for any leakage but I need to clean the 20 years of oil off everywhere before I can see if anything new is dripping...

[estoguy]

Castrol Edge 5w50