why does bmw require 10w60 ?

[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?

 

[Lead Shoes]

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.

 

[1 FMF]

i don't know anything about bmw models, especially the M-series and whatever engines they use.

you say CAFE isn't there, but I don't understand. How can BMW sell the car/engine in the US then?

 

[aquariuscsm]

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.


^^Exactly. BMW knows they`re cars aren`t going to be granny-driven grocery getters. They`re going to be driven the way a sportscar/high-performance car is meant to be driven,fast and hard. I just wish high performance oils were easier to find like they used to be.

 

[Lead Shoes]

CAFE mandates certain emissions to meet and MPG numbers, BMW cares about neither with the M cars, their focus is not on pleasing the tree huggers, but for real drivers with those cars, they pay the fines and produce them anyway.

The reason cars use such light weight oil here in the USA is to wring every last MPG out of the engine they can, cars that are recommended to use a 5w20 here will ask for 10w40 in Australia because they do not have CAFE requirements so they don't have to stretch 1.2% (if that) better fuel economy out of the car.

The average M car has the HP of 4 of my Honda's, and weigh only slightly more...

 

[1 FMF]

so by this logic, if I were to drive my altima which has a 4 cylinder or my camaro with an LS1 like a BMW m-series, I should run 10w-60 oil in those?

 

[CATERHAM]

Eccept most M series cars in NA ARE "granny-driven" by Poseurs.
My dentist is the typical buyer. Loved the high performance image of his M3 but rarely drives over 70 mph and has never even seen 100 mph! He finally got tired of it (didn't like the stiff ride) and got an Audi A8.

If you don't track the car a 40wt like M1 0W-40 is a much more suitable engine oil.

 

[JOD]

Originally Posted By: CATERHAM

If you don't track the car a 40wt like M1 0W-40 is a much more suitable engine oil.


Agreed. I don't think it's a matter of being a poser as much as that fact that you'd end up in jail if you drove that car on public roads in a manner that would heat up the oil to the degree that you'd need a 60W.

 

[CATERHAM]

Originally Posted By: 1 FMF
so by this logic, if I were to drive my altima which has a 4 cylinder or my camaro with an LS1 like a BMW m-series, I should run 10w-60 oil in those?

Not the 10W-60 which is ridiculously heavy and your oil pump would never be out of by-pass mode, but possibly a slightly heavier oil. But some engine designs are better at controlling engine oil heat than others.
I've always been impressed with Chevy engine durability on the track running the light spec' 5W-30 oil even with oil temp's that can get very high, approaching 300F, with no signs of sever engine wear; truly amazing.

 

[A_Harman]

http://www.redlineoil.com/news_article.aspx?id=13

Here's an article on Red Line's website about products they make for Bimmers. Even they don't recommend 10w60:

"Most E36 and E46 cars run fine on the recommended 5W30-even with all but the most dramatic aftermarket mods. The need for 10W60 motor oil in the M-cars is questionable to many (including Red Line, as we've seen customers run as light as 5W30 in E46 M3s without issue), but we now offer this product for sale in North America (we have sold this product in Asia for many years). Folks like Bavarian Autosport smartly recommend that that their Red Line customers use the lightest weight that's appropriate for seasonal conditions. We don't argue that."

BMW should stop trying to gloss over their inability to engineer proper bearings and oiling systems by spec'ing absurdly high oil viscosities.

 

[Klutch9]

Originally Posted By: A_Harman
http://www.redlineoil.com/news_article.aspx?id=13

Here's an article on Red Line's website about products they make for Bimmers. Even they don't recommend 10w60:

"Most E36 and E46 cars run fine on the recommended 5W30-even with all but the most dramatic aftermarket mods. The need for 10W60 motor oil in the M-cars is questionable to many (including Red Line, as we've seen customers run as light as 5W30 in E46 M3s without issue), but we now offer this product for sale in North America (we have sold this product in Asia for many years). Folks like Bavarian Autosport smartly recommend that that their Red Line customers use the lightest weight that's appropriate for seasonal conditions. We don't argue that."

BMW should stop trying to gloss over their inability to engineer proper bearings and oiling systems by spec'ing absurdly high oil viscosities.


While I want to agree with this, I thought I remember reading a few years back about the E46 M3's and the 10w-60 spec. Now, let me preface the following by saying that I'm only speaking from memory, NOT hard fact. We proceed... Evidently, the early E46 M3's were spec'd for 5w-40 oil. But after a number of oil-related failures, 10w-60 was implemented as the spec for that motor. Every 'M' motor since then has had the 10w-60 oil spec.

::flame suit on::

 

[mechtech2]

The high sped highways in France and Germany will allow you to push the car to it's limits.
In the USA, 99% of driving is sedate.
German cars have always spec'd a thick oil.

 

[carwreck]

Originally Posted By: 1 FMF
...
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...
why?

BMW 10w60 recommendation is only for specific M engines.

The reason: to prevent oil leaks/oil burning.

From BMW Service bulletin http://homepage.mac.com/ianlindvig/BMWEngineOils.pdf

"....engine oil consumption will increase when Castrol Formula RS 10W-60 Synthetic Oil
or Castrol TWS Motorsport SAE 10W-60 Synthetic is diluted (topped up with other low viscosity
synthetic engine oils)."
______________________________________-

1999 Olds GLS 3.4L

 

[CATERHAM]

Yes there was a bearing issue back then and the 10W-60 was a "quick fix" recommendation. But the issue is behind them.
Again most M series engines won't even see 100C oils temp's driven on the street.
Even track driven cars don't need such a heavy oil as RL states. A freind of mine who had an early E46 M3 was a BMW club instructor and thrashed his car routinely on the track using M1 0W-40 (once out of warranty) without issue.

I have no idea why BMW continues to recommend the oil in NA. Although the spec' Castrol TWS 10W-60 oil is know to shear down a lot in service so in theory the oil could possibly test minimum viscosity limits after 15,000 miles on the oil, plus fuel dilution, on a very hot day after hours of flat out lapping at the track.
To the best of my knowledge, BMW is the only car company that still does spec' that oil grade. Ferrari no longer does on any of it's current cars, in fact the spec' oil is a rather light 3.68cP HTHSV 5W-40.

 

[CATERHAM]

Originally Posted By: mechtech2

In the USA, 99% of driving is sedate.
German cars have always spec'd a thick oil.

For other than M series gas engines the spec' oil is 5W-30.

 

[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. Also, my experience with older German cars is that they recycle parts and techniques for years, and are in many ways very conservative / cautious with their engineering. Consider the 1980's GM diesel engine from gas conversions, and skipping the water filter/drain, etc. using a quickly engineered 350 adaption rather than the in house truck diesel they already had. I doubt that would ever happen in Germany. So thick oil and lots of it sounds sooo German, but downsizing to meet US CAFE standards is real life.

 

[cchase]

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.


Oh come on, stock SBC's (and BBC's) had production car records for solo top speed endurance runs for years in the Corvette and 454SS trucks (and probably others). It's stupid to say a Corvette engine in an Opel failed because the driving in Europe is just so incredible the inferior American engine can't possibly cope.

 

[d00df00d]

BMW doesn't "require 10w-60." It recommends a specific product -- Castrol TWS -- for its M cars, and that product happens to be a 10w-60.

Here's why, as far as I've seen:


1. It was, and continues to be, co-developed by Castrol and BMW M, alongside BMW M powertrain engineers.

2. It was, and continues to be, developed specifically for BMW M engines.

3. It is descended from a product with a very long and extremely successful history in racing (look up Doug Hillary's comments on the subject -- he actually worked on it).

4. It works in any situation, from commuting to extended track sessions.

5. It works in any climate, from the coldest to the hottest.

6. It works for extended drain intervals.

7. It manages to accomplish all of the above despite having a relatively clean (i.e. light) additive package.


In other words, it's one of the most advanced and highest-performing products you can buy from the major companies. Viscosity is only a small part of the story.

Somewhat more on-topic (relative to the OP), I am extremely skeptical of any third-party product claiming to be a substitute for Castrol TWS in M engines. One glance at my sig should assure everyone that I am not exactly stuck on big name-brand products, but I have a hard time believing that any outsider could match or beat TWS.

 

[CATERHAM]

I must admit, high oil consumption when crusing at very high speeds (150+ mph) is a factor I over looked, but it does make sense. But it just makes one question even more why the 10W-60 grade is still spec'd for NA where such sustained speeds are simply not possible.

 

[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?