BMW E91 325iTouring用機油Motul太稀?

下面係 北美 E90 3系嘅 325i同 330i 說明書抄出嚟嘅. BMW出廠已經係用全合成 Synthetic Oil, 而就算唔用原廠機油 (Castrol 產品), 都一定要用全合成油. 黏度嚟講, 5W40 同 5W30 都係測試過喺任何合理溫度下行駛都冇問題. 美國嘅地方比香港更凍同更熱更濕嘅地方都有, 所以呢個黏度喺香港用一定冇問題.

而Motul Synthetic Oil 亦通過 API SH 標准, 同埋 BMW LL-98, LL-01 同 LL-01 FE 標準, 所以你用呢隻油應該冇問題.

http://www.motul-asiapacific.com/hongkong/eng/fact_sheets/maker_approval.html

Specified engine oils
The quality of the engine oil selected has critical significance for the operation and service life of an engine. BMW continuously approves specific
oils after confirming their suitability for use in its vehicles with extensive testing.

Use only approved BMW High Performance Synthetic Oil . If you are unable to obtain BMW High Performance Synthetic Oil, you can add small
amounts of another synthetic oil between oil changes. Use only oils with the API SH specification or higher.

Ask your BMW center for details concerning the specific BMW High Performance Synthetic Oil or synthetic oils which have been
approved.

You can also call BMW of North America at 1-800-831-1117 or visit this website:
www.bmwusa.com to obtain this information.

Viscosity ratings
Viscosity is the oil flow rating as defined in SAE classes.
The selection of the correct SAE class depends on the climatic conditions in the area where you typically drive your BMW.
Approved oils are in SAE classes 5W-40 and 5W-30 .

These oils may be used for driving in all ambient temperatures.

2010-03-12 12:08:23 補充：
馬力係扭力乘引擎轉數乘常數出嚟嘅一個功率.
自然吸氣引擎, 要大扭力就要大cc, 而家cc唔轉得, 即係可以靠扯高個引擎轉數.
你嘅325i係用北美版 N52 3.0L引擎還是歐洲版前期 N52 2.5L引擎呢? 如果係 3000cc, 咁你可以嘗試去砌番D改變進氣排氣活瓣嘅部件整番個高輸出嘅 N52B30 (差不多係 internal rebuild), 如果你 2.5L, 就只可以靠扯高引擎轉數. 我諗你如果可以改動ECU令到轉數可以踩到上九千幾轉就應該去到嗰個馬力
In a nutshell, 冇平嘅方法

2010-03-12 14:15:21 補充：
如果你真係諗住可以改ECU 就將部自然吸氣嘅 325i改到330i嘅 performance, 可以話係痴心妄想.
改到行車電腦, 出面都冇人改到波箱電腦. 你放棄吧啦.


或者你可以等呢間公司出supercharger kit 嘅.
http://www.mosselmanturbo.com/index.php?id=147&L=0

2010-03-12 18:02:34 補充：
To give you a short answer, if 325i vs 2.0T FWD, then 325i. If 325i vs. 2.0T Quattro Avant, that's a very close call.

Please start a new question if you have other question not regarding your original engine oil question.

Check your owners manual and see if the 5W30 is what required. It will supply enough protection and oil pressure with the correct weight of the oil *AND* amount of oil. Motul is one of the good oil selection. But, beware of synthetic oil. Once you decided to use synthetic oil, you should NOT use the normal engine oil. If you switch back and forth, engine gaskets and seals will tend to leak after some years.

Try to stay away from Redline engine oil. It is designed for racing and should change oil after EACH race. Redline has a different formula which has higher lubrication and less friction. However, this results in less protection. Redline is not really for daily drive but racing.