You take the weight of the individual parts and mix accordingly;
1 kg fuel could be
70% Methanol = 700g / 0,791= 884,95 ml
20% Klotz BeNol = 200g / 0,962= 207,9ml
10% Nitro = 100g / 1,138= 87,87ml
// 1180,72ml of fuel
That makes sense, now the question becomes do you sell that fuel as 10% nitro fuel, 10% nitro by weight or 87.87/1180.72X100 ie 7.4% nitro fuel
My guess would be that the latter would be the case, in which case no one is being ripped off, but the assumption is always for option one.
I would be interested to know for sure.
That is a good question and hard to tell if you donĀ“t know the mfg or someone that has a lab.
Morgan fuel specifies that itĀ“s in weight, but when they donĀ“t spec it, we can only guess...
If I would give my own subjective view of what I think, then it would be that most mfg use weight and then add slightly more to it to be able and tell us that they have more then whatĀ“s specified.
Also, as long as they donĀ“t specify what method they use, they can use both... Weight for nitro and volume for oil and methanol.
One thing to remember also is that here in Europe they do take fuel samples in car racing as there is a limit in how much nitro thatĀ“s allowed.
As most of the fuel mfg use PAG for synthetics in their fuel and those oil are slightly heavier, they couldn't mix nitro in volume and still be legal for racing (in high oil % fuel). Just sayin'...
I did try some fuel mixes to see when it was close to the bought racing fuel and right around 20% by volume it was close to a couple of top brands thatĀ“s 25% fuel...
A very subjective approach as I donĀ“t know what oil etc they use, but it gave me an idea of how things really are.