Originally posted by hauckf
If I do have a Ax to grind, it is with the one manufacturer who advertises and labels his product as 15% nitro and 18% oil, when the actual content is about 11.3% nitro and 15.6% oil by volume. Those differences I do think are significant. But then, that's just my opinion; I could be wrong.
And this I think is the point to the whole thread. Seeing I mix my own fuel (and being an Aussie anyway so I've never seen the brands mentioned) I can quite imagine someone buying a gallon of fuel that's cleary marked 18% oil and 15% nitro...but hidden right down the bottom in fine print it might say "calculated by weight". And that to most people wouldn't mean a thing.
As for the coefficients of expansion, that should be fairly easy to get a close idea by simply filling a length of clear tubing with about a metre of each fluid. If it's a cold day outside then leave it out there until it stabilises to the outside temp and measure the height of the fluid. Bring it inside and again let it stabilise and remeasure. It'll work just like a thermometer. All you need to know is the temp of the ambient conditions or if you've got a wire thermocouple then you can check the actual temp of the fluid. I think I might even try this
