You can't distinguish them but there is a big difference with its boiling point...lower viscosity, has lower boiling point so you could use them during cold weather as it is easier for the oil to reach the reccomended teperaure to run the car normally. In tropical areas where the climate is usually hot, or when you race, you should use an oil with a higher viscosity so it won't boil easily.ThurzNite said:i went 10w-30 cuz i was hoping it was thicker...but i can't tell the diff.
It's 30-weight oil. It just behaves like 5w at low temperature. It's not thinner. You better hope it's not thinner.SHAWN said:5w-30 !!! If you are looking for every ounce of power you can get the 5w-30 is thinner so it will take less resistance to make it flow !!!! Less resistance = more power .....
yea actually it is thinner , try dumping out a 10w-30 then dumping a 5w-30 ...the 5w is thinner right from the bottle .....in fact some of the newer cars like some hondas and fords are using a 0w-30 oil , so it is geting even thinner , next drag race I am going to run a 0w-30 and see if it helps .....kenshi said:
It's 30-weight oil. It just behaves like 5w at low temperature. It's not thinner. You better hope it's not thinner.