What about Mobil 1™ V-Twin 20W-50 motor oil? How is that different from Mobil 1 for passenger cars?
Mobil 1 V-Twin 20W-50 fully synthetic motor oil is designed for air-cooled, large-displacement bikes. Because of their design, these engines can generate very high localized oil temperatures and high overall bulk-oil temperatures.
As you know, a typical air-cooled V-twin's rear cylinder gets a lot hotter than the front cylinder – it's a matter of airflow. When it's hot out and you're stuck in traffic, the oil temperature in your bike climbs rapidly. Above about 250°F, conventional motor oil is going to break down. Mobil 1 V-Twin 20W-50 fully synthetic motor oil is good to above 300°F.
Like Mobil 1 Racing 4T 10W-40, Mobil 1 V-Twin has high levels of phosphorus/zinc and the same high-temperature detergent technology for superior wear protection and engine cleanliness, even at elevated oil temperatures.
With Mobil 1 V-Twin oil, you can go the full length of the manufacturer's recommended oil change intervals with ease. 意思是說像氣冷式V型雙缸引擎(如很多美式機車),特別是在塞車狀況下(又以後方汽缸為甚),溫度容易飆升到華氏250以上,傳統機油容易失效,所以除了推薦Mobil 1 Racing 4T 10W-40一次搞定之外(個人推想因為它比較貴當然要你買),也推薦Mobil 1 V-Twin 20W-50。