GT35R_BMW;497936 said:
Guys,
Oil temp doesnt really concern me.
Have you check out the oil pressure during hard driving between the two oils or scuffing marks on bearings after 100,000kms?
Oils will be oils..Most oil works on most cars and what you pay is what you get.
Like said. You wanna be economical and you wanna drive a high performance car its up to you.
These TWS were recommended, sold and imported directly from BMW USA. If you wanna doubt the manufacturers of your own vehicle its your call.
Cheers to all!
First of all in BMW's higher powered cars, there is always an oil temp. That itself speaks volume of its importance. What if there is an oil pressure gauge, is it more important than oil temp gauge? Pressure gauge will only show me the oil pump is working, but it won't tell the state of the engine.
To reply your question on the oil pressure, could you share with us what is the difference in oil pressure between TWS and EDGE Sport? Do you have any data or are you just posing a question to me?
If its the latter, this is what I learned in fluid dynamics....from the density of the oil (check the info I provided earlier), the EDGE Sport (despite rated at 30C) has similar density to the TWS (rated at 15C). As a matter of fact, oil will become denser when its temperature is lower. I do not have the information here, but suffice to say there is great likelihood that Edge Sport will have similar density, if not higher than TWS at 15C.
In layman's term, it means when 2 objects with similar density is compressed, the pressure should be more or less similar. The experiment done in school those days was to put oil, water, or air in a syringe with one end blocked, and the push the plunger on the end.
Water with a density of close to 0.995 at room temp (30C) is practically impossible to be compressed, where as air with a density of 0.0012 at 20C is easily compressible.
Now you mentioned this "Less oil pressure = more friction = more heat", getting into thermodynamics
To me this statement is very misleading as lesser oil pressure doesn't cause more friction in some cases which then generates more heat. Lesser oil pressure will generate more heat for sure because of heat soaking, meaning to say the oil circulation is slower and hence the heat rejection rate via the oil cooler and oil sump is slower.
Imagine of an engine bottom end filled up with oil to the brim for discussion sake, the conrod and bearing soaked in oil. Oil pressure is more or less zero with the pump disengaged, is there more friction, or lesser friction? If friction is the same with the pump running, why does the temp go up? One can then safely conclude the temp goes up due to heat soaking.
As for scuffing on the bearings, irrespective of what oil you used, if its not changed regularly and becomes contaminated, scuffing will occur. There is no evidence that TWS will lessen bearing wear compared to EDGE sport, and as t2ribena has shared, scuffing do also happened with engines filled with TWS.
Yes, you get what you paid for and in this case the main difference is the Group 3 and 4 oil base and that probably explain the marginal improvement in terms of boiling temperature, which to me is important. Then again, when my oil temp hits 125C on the track, I usually will ease off and upshift at a lower rpm. If anyone is insane enough to test the boiling temp of the oil, chances are the engine would have seized before he/she reached the boiling temp of the edge sport, let alone the TWS.
No one is doubting the manufacturer's recommendation and TWS is not the only oil specified for usage in the M cars. The formula RS which is superceded by the Edge Sport is also approved for usage, and Castrol themselves has confirmed this with me via email.
Cheers
