WHICH OIL FOR E39 M5??

Stephen the help sections say:

It is VERY important that you use the correct oil in the E39 M5 engine (S62 B50). This is due to changes made to the cylinder wall material from around Feb 02. If your car was built around this point I would recommend using the engine number to determin which oil to use.

Upto Feb 2000 use either Castrol TWS Motorsport SAE 10W-60 or Veedol Synthetic Z SAE 10W-60 which is also recommended by BMW.

After Feb 2000 you have a greater choice of oils availible to you, I would recommend Castrol SLX LL01 SAE 0W-30 having been using it without a problem since the introduction of the modified engine.

Hope this helps.

Andy (BMW Tech)

Just ensure that the oil used is BMW LL01 Approved.

If you have problems sourcing it, I have four different ones.

You can always email me.

Cheers

Simon

http://www.opieoils.co.uk/lubricants.htm

oilman wrote: Totally agree 100% and it's what I have been saying all along. You can in fact use any 0w-30, 0w-40, 5w-30 or 5w-40 that is approved by BMW to the specific LL01 specification. Cheers Simon

Thanks for the confirmation Andy and Simon.

If any of you get BMW Car Magazine you will see in November's issue a letter from me on page 38, which I sent over 2 months ago, before discussing on the Forum or contacting Oilman.

You will note that the Mag contacted a main dealer and a specialist, both of whom advise (wrongly!!) TWS 10w-60.

I guess the message is still not getting through!

One last question, probably for Andy, - I thought my 2001 M5 had hydraulic tappets; I am surprised to find they are (what I thought obsolete!) "bucket and shim"!  Is this really right??

Regards

STEPHEN B

Darren,

Your M5 should have been filled with Fully Synthetic LL-01 0w-30 (e.g. Castrol SLX) at its last service if done by a main dealer.  Therefore you should top up with the same.

Your service invoice should itemise the materials and the oil used.

If not it's probably worth checking what was used and topping up with the same.

However if your main dealer used TWS 10w-60 which is not an LL-01 BMW approved oil, he was wrong.  He should reread the BMW Technical bulletins.

I hope the Oilman reads these posts, because he is the expert - I am only passing on what I have learned by many hours of research!

Regards

STEPHEN B

Ok, here's a quick description of what happens if an oil is not suitable for the engine.

Surely the thicker the oil the better!

This isn't always true - even when using a petroleum oil.

Although it is true that heavier viscosity oils (which are generally thought of as being thicker) will hold up better under heavy loads and high temperatures, this doesn't necessarily make them a better choice for all applications.

On many newer vehicles only 0w-40, 5w40 or 10w40 engine oils are recommended by the manufacturer. If you choose to use a higher viscosity oil than what is recommended, at the very least you are likely to reduce performance of the engine. Fuel economy will likely go down and engine performance will drop.

In the winter months it is highly recommended that you not use a heavier grade oil than what is recommended by the manufacturer. In cold start conditions you could very well be causing more engine wear than when using a lighter viscosity oil.

In the summer months, going to a heavier grade is less of an issue, but there are still some things to be aware of.

Moving one grade up from the recommended viscosity is not likely to cause any problems (say from a 10w40 to a 10w50 oil). The differences in pumping and flow resitance will be slight. Although, efficiency of the engine will decrease, the oil will likely still flow adequately through the engine to maintain proper protection. However, it will not likely protect any better than the lighter weight oil recommended by the manufacturer.

Moving two grades up from the recommended viscosity (say 10w40 to 10w-60) is a little more extreme and could cause long term engine damage if not short term. Although the oil will still probably flow ok through the engine, it is a heavier visocosity oil. As such it will be more difficult to pump the oil through the engine.

More friction will be present than with a lighter viscosity oil. More friction means more heat. In other words, by going to a thicker oil in the summer months, you may actually be causing more heat build-up within the engine. You'll still be providing adequate protection from metal to metal contact in the engine by going with a high viscosity, but the higher viscosity will raise engine temperatures.

In the short run, this is no big deal. However, over the long term, when engine components are run at higher temperatures, they WILL wear out more quickly.

As such, if you intend on keeping the vehicle for awhile, keep this in mind if you're considering using a heavier weight oil than the manufacturer recommends.

The best advice is to is to stay away from viscosity grades that are not mentioned in your owner's manual.

Cheers,

Simon