How to measure the right amount for a special mixture?

[mrx79]

Hallo,

i have a quick question about mixing my Water / Methanol / Nitromethane mixture.
for example, if i want to make a 60/20/20 W/M/N mixture... how sould i measure the different fluids?

by Weight? by Volume?

i ask because when i remember my chemical class correct then Nitro has another specific weight then water and methanol right?

so how can i be sure that i get exactly my wanted mixture?

does temperature plays a role?


Hope to get some help
Thanks
Malte.