It they are the same weight oil as in SAE 30 weight oil there is no difference and they are identical. 30 weight oil is 30 weight oil synthetic or conventional.
weight of oil is lighter than water
Just the opposite, 30 weight oil is thinner that 40 weight oil and will flow better at low temperatures.
It is the weight of the multi-vicosity oil. The 10 is the weight of the oil when cold. The W stands for Winter. The 40 is the weight of the oil when it gets hot.
SAE 10 weight oil
10w30 weight oil.
what weight oil for 6.5 engine
The weight of the oil and flow rate. The 5w30 will flow easier when cold than the 20w40. It is 5 weight oil when cold whereas the other is 20 weight when cold. When the oil reaches full operating temperature the 5w30 is 30 weight oil and the 20w40 is 40 weight.
A US gallon of 90 weight oil weighs approximately 6.8 pounds. An Imperial gallon of 90 weight oil weigh approximately 8 pounds.
Polaris has their own special "fork oil". 7.5 weight is equivalent to polaris oil or use a 10 weight to improve dampening.
hd 30 weight oil of your choice.
It will do no damage if you just added a little of the wrong weight oil. However if you changed the oil and poured in the wrong weight I would suggest your remove that oil and pour in the correct weight.