20W-50 motoroil is the correct weight for many air cooled engines. This weight of oil is thicker and tolerates higher engine temperatures. Harley Davidson motorcycles, turbocharged automobiles are two common uses. One additional consideration would be the use of synthetic motoroils as these oils do not suffer breakdown (boiling off, burning, blackening) at higher engine temperatures. Examples: Mobil One Synthetic 20W-50.
20w-50 indicates Synthetic-oil
20w-40 20w-50
90n 20w
Only the weight of the oil, 20w 40 is thiker than the 15w40, 20w 40 is the best oil for the old cars although 15w40 is very easier cold start ...
energy = power * time = 20w * 1hr = 20 watthours or 0.02 kilowatthours
10w-40, 20w-40 & 20w-50 are best grades, Brand which i preffer is "ZIC"
90n 20w
20w/50
20w-50
20w-50 is what i use but yamaha recomends 20w-50 yama lube has things in it to help the cluthes and transmission
20w 50
4002 (or) 20L by 20W