why does bmw require 10w60 ?

[CATERHAM]

d00df00d, I agree with most of what you've said.
I just find BMW's engineering approach to be very odd indeed including the use of a variable red line during the warming up process; unnecessary complexity. But bless them for their unconventional thinking.

It's like the iconic Porsche 911; a flawed design, superbly executed.

 

[A_Harman]

Originally Posted By: bmwjohn
it probably is not relevant but german cars always use MORE oil than most American car designs. Years ago Opel put a small block Chevy Corvette engine in the mid size Opel (Commodore?) as a cheap way to build a top of line car. The engine failed because of lack of oil. 5 minutes at high speed is NOT the same as 100 mph for 1 hour.


100mph for an hour is not a challenge for a small-block Chevy. My 1985 Corvette in 4th-overdrive would be running 105mph at 3000rpm, at which point the engine was loafing close to its peak torque output. When GM sold Corvette's in Europe in the late-80's, they were equipped with larger oil coolers to deal with sustained high speeds on the autobahn.

 

[A_Harman]

Originally Posted By: 1 FMF
Quote:
M5 (S62 engine) produced from 3/00 and all Z8:
-- The S62 engine incorporates redesigned piston rings from 3/00 which permit the use of BMW High Performance Synthetic Engine Oil SAE 5W-30.
-- The recommended engine oil for all Z8 vehicles and M5 vehicles (produced from 3/00) is BMW High Performance Synthetic Engine Oil SAE 5W-30.


from the TSB link above, is this admittance that BMW (the greatest automotive engineers on the planet) screwed up piston rings?


Yes, but every auto manufacturer has similar problems. It's just that when BMW has to specify the engineering equivalent of Lucas Oil Stabilizer to keep rod bearings in its top of the line performance engine, it is regarded by the true-believers as evidence of their superior engineering. Then they search far and wide for the magic elixir that will make their engine live happily ever after.

Like Caterham says, most drivers in the US never push their cars to that limit.

 

[jaj]

This is truly a full face-palm moment.

First, the words in the quote from Liqui Moly are just marketing gobbledy-gook. As d00df00d said so eloquently, the M engines don't need a 10w-60, they need TWS, which happens to be a 10w-60.

Second, the engines can run fine under light duty with just about any oil.

However, unlike most grocery getter engines, BMW M engines are built to operate pretty much continuously at any point inside their "design envelope". There are no "nobody will ever actually do this" shortcuts taken. So, as Ford does with the Boss 302 and the GT500, BMW uses an oil that ensures that the idle oil pressure is adequate when the oil temperature is at its maximum, say after an extended run at 7000+ RPM (8000+ RPM for the new V8).

TWS is the same oil that BMW Motorsport uses in their full-race engines, and it's in the M Division engines for the same reason: it works, over and over and over again.

 

[Trav]

Until just a couple of years ago Castrol's premium motorcycle oil in Germany was RS 10w60 and listed for sport or high speed and not only for BMW. Now they have a 10w40 that supposedly provides the same level of protection, time will tell.

I know of more than a few MB V12 twin turbo cars running the 10w60 as well but they are not putting around at 100mph either.

 

[CATERHAM]

And GM can acheive the same lubrication performance in it's 638 hp ZR1 on an inexpensive HTHSV 3.1cP 5W-30.

 

[dailydriver]

Originally Posted By: CATERHAM
And GM can acheive the same lubrication performance in it's 638 hp ZR1 on an inexpensive HTHSV 3.1cP 5W-30.


Yes, but that car/powerplant doe NOT have to wind to the stratosphere to make that power, although it's red line IS fairly high for a decent sized, boosted, pushrod V-8.

It's bearing clearances are also probably MUCH tighter than the M cars'.

There is also no VANOS system, or other uber-techie tricks in it's valvetrain, but I'm not even sure that is/was any reason for the M Works engineers to spec the TWS.

 

[artificialist]

Originally Posted By: CATERHAM
And GM can acheive the same lubrication performance in it's 638 hp ZR1 on an inexpensive HTHSV 3.1cP 5W-30.

Just because the Corvette can use oil with an HTHS of 3.1 does not mean it is the best oil for the job.

 

[CATERHAM]

Originally Posted By: dailydriver
Originally Posted By: CATERHAM
And GM can acheive the same lubrication performance in it's 638 hp ZR1 on an inexpensive HTHSV 3.1cP 5W-30.

Yes, but that car/powerplant doe NOT have to wind to the stratosphere to make that power, although it's red line IS fairly high for a decent sized, boosted, pushrod V-8.

It's bearing clearances are also probably MUCH tighter than the M cars'.
There is also no VANOS system, or other uber-techie tricks in it's valvetrain, but I'm not even sure that is/was any reason for the M Works engineers to spec the TWS.

We're getting away from the main point that the TWS 10W-60 is much heavier than necessary for all street us in NA and most track use.

 

[hattaresguy]

Originally Posted By: Brenden
Because CAFE isn't there to make them recommend a 40 weight instead, and a car of that caliber puts out a lot of power and heat, and they manufacture them knowing you are going to push them to the limits, so they recommend the appropriate oil.


Nonsense, AMG, Mercedes, and Porsche beg to differ and spec Mobil 1 0w40.

BMW doesn't make the big HP motors that AMG does, or the high revving flat 6's that Porsche loves.


M simply works with Castrol and this is what they say works with their motors.

 

[CATERHAM]

Originally Posted By: artificialist
Originally Posted By: CATERHAM
And GM can acheive the same lubrication performance in it's 638 hp ZR1 on an inexpensive HTHSV 3.1cP 5W-30.

Just because the Corvette can use oil with an HTHS of 3.1 does not mean it is the best oil for the job.

Any pray tell what oil would be better?

 

[OVERKILL]

How many of the M engines actually call for the 10w60? The S62 at least calls for just an LL-01, which is a 3.5 HTHS oil.... Satisfied by a 5w30.

 

[jaj]

Originally Posted By: OVERK1LL
How many of the M engines actually call for the 10w60? The S62 at least calls for just an LL-01, which is a 3.5 HTHS oil.... Satisfied by a 5w30.


The S52 was the last engine not to call for it at all, and the S62 had it as optional but not required. Neither engine produced anything like 100 horsepower per liter naturally aspirated. The S62 only produced 80 horsepower per liter.

On the other hand, it's "the only oil" for the S54 inline 6, the S85 V10 and the S65 V8. These are all high-revving naturally aspirated BMW M division engines that produce over 100 horsepower per liter.

 

[OVERKILL]

Originally Posted By: jaj
Originally Posted By: OVERK1LL
How many of the M engines actually call for the 10w60? The S62 at least calls for just an LL-01, which is a 3.5 HTHS oil.... Satisfied by a 5w30.


The S52 was the last engine not to call for it at all, and the S62 had it as optional but not required. It's "the only" for the S54, the S85 and the S62.


Thanks!

 

[jaj]

Originally Posted By: hattaresguy
...BMW doesn't make the big HP motors that AMG does, or the high revving flat 6's that Porsche loves...


Don't whistle the BMW play dead so easily. BMW produced the S70/2 V12 6.1 liter, 618 horsepower engine for the McLaren F1 in 1992, long before those numbers were "normal" in any sense. BMW also owns Rolls Royce, which has some awesome power plants up to 560 horsepower. BMW just doesn't strut its bling the way that AMG does. Its racing division, BMW Motorsport produces cars that compete with Porsche at pretty much all levels. The four-door grocery-getter version of the newest BMW M3 produces 414 horsepower at 8400RPM, which is more than all the naturally aspirated 911's except the GT3, even after you correct for displacement.

 

[jaj]

Originally Posted By: CATERHAM
...We're getting away from the main point that the TWS 10W-60 is much heavier than necessary for all street us in NA and most track use.


The OP wanted to know why Lubro Moly was advertising 10w-60 oil for BMW's. Whether or not 10w-60 is heavier than necessary is a debate we collectively lack the information to settle.

 

[ledslinger]

The BMW M oil spec reminds me of marine engine oil specs in one regard, the oil must cope with potential duty rather than likely duty. Most small pleasure boats see an occasional high speed run of short duration and work fine on passenger car oils.

Put the same engine in a cruiser and load it over 75 percent for 10 hours and PCMO oil may be wasted following just this run.

Economy isn't a high priority with M cars so engineers don't have to spec an oil considering cost or widespread availability. If you were BMW what oil would you spec? They chose the one they have confidence in and I haven't ever read of failures blamed on this oil.

One area that BMW succeeded in was creating a lube spec that is easy to fulfill and recognize. If TWS could be legally called a 10W50 it would have increased the incidence of owners substituting inferior oils possibly resulting in problems.
The seemingly outrageous viscosity and spread is legendary, and may enhance adhering to the spec, and also to seeking ways around it.

 

[BMWTurboDzl]

Originally Posted By: jaj
Originally Posted By: OVERK1LL
How many of the M engines actually call for the 10w60? The S62 at least calls for just an LL-01, which is a 3.5 HTHS oil.... Satisfied by a 5w30.


The S52 was the last engine not to call for it at all, and the S62 had it as optional but not required. Neither engine produced anything like 100 horsepower per liter naturally aspirated. The S62 only produced 80 horsepower per liter.

On the other hand, it's "the only oil" for the S54 inline 6, the S85 V10 and the S65 V8. These are all high-revving naturally aspirated BMW M division engines that produce over 100 horsepower per liter.
And all the new M's use BMW 5w-30 (this engine family is turbocharged as well).

 

[BMWTurboDzl]

Originally Posted By: 1 FMF
reading an ad in motor magazine, page 42 december issue,

Liqui Moly 10w60:
" bmw promises a unique driving experience. Its M-Series gives BMW drivers the extra kick. These cars need special motor oil like fully synthetic LIQUI MOLY Synthoil Race Tech GT1 10W-60. High performance oil made in Germany for high performance cars made in Germany. The wide viscosity range indicates the high performance of LIQUI MOLY Synthoil Race Tech GT1 10W-60."



why?
This weight was spec'd for a limited number of BMW "M" cars which is their high performance line. These cars are essentially race.cars for the street. BMW has been paired with Castrol for years and they ended up using an ester derivative of an older Castrol product for a smaller number of "M" engines. TWS is the name another companies sell an alternative in same weight. The brand you've mentioned is an alternative.

 

[SilverC6]

The BMW Castrol TWS is an oil that BMW has long history with in racing applications.

The S54 3.2 liter is an application needing maximum protection.

That's why BMW requires the TWS.

Would I use Lubro Moly 10W-60? Only if I couldn't find any TWS anywhere.

I wouldn't want the S54 in my Z4M Coupe to let go because I saved a couple of dollars on an oil change.