機油聖經
主要是講解,HTHS,TBN,粘度指數等參數說明，配合，下面這個對照可查到每種油的屬性。
各品牌機油 40/100粘度,HTHS,TBN,粘度指數,傾點,閃點等參數匯總2.55版
搭配之前討論串
http://www.focus-sport.club.tw/viewthread.php?tid=254097
基本上 Viscosity@100、Viscosity@40 不用看。
VI - 越高越好，但持續時間要看TBN.
TBN - 耐久度。可惜很多油沒列出 TBN
下面這個網站有個Tool，將自己所使用的油 @40 跟 @100 輸入，Temperature 填入80後，(80是為了放大曲線，比較好看)
它會根據 SAE 5W-30/ 10W-30/ 15W-40 / 20W-50 最低規範所畫出的曲線，並以5度C為單位，Show出當時 Viscosity 。
以上面機油表格第六瓶，CastrolEDGESport 5W-30(UK) 11.9 73.4 來做範例
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根據這張圖可以得知幾點：
- VI 是均值，整個Viscosity 是非線性曲線。
- @40 及 @100 則是在分別在40度及100度下，Viscosity的值。
- 由Temperature 表可得知，125度時 Viscosity = 7.3
So, 依車子油溫落在甚麼等級來選擇合適的油，可以先跟據最上面那個油的列表，在用下面的工具，就可以先測，不用先拿車子實驗了。
Viscosity Index Calculator
Viscosity 曲線圖
============ TBN / TAN ===================================================
根據說明，這兩個東西跟跑不跑的快無關，主要是機油能用多久，而要查當下的TAN 也只有化驗一途 (不可能開一開，每個月拿去驗吧)。
所以完全不用參考，因為一般人無法測量，且衰退程度也並非線性，就算高退粉快也是無用。
Total Base Number (TBN)
TBN is a property usually associated with engine oils. It is defined as the oils' ability to neutralize acid. The higher the TBN, the more acid it is able to neutralize. This quality is also referred to as alkaline reserve and is directly proportional to the amount of active detergent contained in the oil. New engine oils typically possess TBN's from 5.0 to 15.0, depending on manufacturer and intended service. As the oil is used, it becomes contaminated with acids and the TBN drops. Generally, TBN levels below 3.0 are considered too low and indicate that the oil should be changed. One cause of TBN depletion relates to the use of low quality, high Sulfur fuel. During the combustion process, this Sulfur turns to Sulfuric acid and in turn, accelerates TBN depletion. As discussed previously, overheating and over-extended drain intervals can cause oil oxidation. The products of oxidation are acidic and will cause the TBN to drop.
總基數（總鹼）
總鹼值是一個屬性通常與發動機油。它被定義為油的能力，以消除影響。總鹼值越高，越酸，可以中和。這樣的品質也被稱為鹼儲備，是成正比的數額活性劑在油中。新的發動機油總鹼值通常擁有從 5.0到15.0，這取決於製造商和預定的服務。由於石油被使用，它被污染與酸和總鹼值下降。一般來說，總鹼值低於 3.0的水平被認為過低，並指出，石油應該有所改變。總鹼值損耗的一個原因涉及到使用低質量，高含硫量的燃料。在燃燒過程中，這種硫變成硫酸，從而，加速總鹼枯竭。如前所述，過熱，過度延長換油週期可引起油脂氧化。其產品的氧化作用，並會導致酸性總鹼值下降。
Total Acid Number (TAN)
TAN is a property typically associated with industrial oils. It is defined as the amount of acid and acid-like material in the oil. Oxidation and nitration resins make up the majority of this material. As the oil is used, acidic components build up in the lubricant causing the TAN number to increase. A high TAN number represents the potential for accelerated rust, corrosion and oxidation and is a signal that the oil should be replaced. Critical TAN numbers are dependant on oil type. Typically R&O and light duty oils have a maximum TAN of 2 while anti-wear and EP oils may have maximum levels of 3 to 4.
總酸量（TAN）
譚是一個屬性通常與工業用油。它被定義為酸量和酸類材料在石油。氧化，硝化樹脂構成了大多數這種材料。由於石油被使用，酸性物質積聚在潤滑油造成譚數量增加。高譚數字代表的潛力加速生鏽，腐蝕和氧化作用，是一個信號，即應更換機油。關鍵數字譚對石油的依賴型。典型的R＆O和輕型油具有最大譚 2，而抗磨損和極壓油可能有最高水平的3至4。
