It's hard to tell until you run it. If stored properly(tightly sealed,somawhat climate controlled and especially away from sunlight)shelf life is a LONG time.
I asked this very question to a Torco Race Fuels representative. Here's a copy of the reply:
Hey Randy,
thanks for the info and the contact..
as for the shelf life, if out of the direct sunlight it WILL last years no matter what anyone tells you, all you have to do is just shake it up lightly just like any liquids. The sunlight is what kills nitro, keep it away from the sunlight and your good for a really long time..As far as the 30% nitro compared to 20% No, in theory your 20% nitro mix will always run cooler. The reason is when you have less nitro you must add more Methanol and that is what cools the engine, so if u run 30% nitro it will run a little hotter because there is less methanol in it, but your correct if you tune it you can get the temperature down. Here is how the componets work within a RC Engine: The Nitro makes the horse power, the 100% synthetic oil keeps the engine lubed at low-medium temps, the castor keeps engine lubed at hot and lean conditions as well as after run, and the methanol is the cooling agent. The nice thing about our methanol and nitro is that its a ll 100% pure and manufactured at our facility in the USA, our nitro and methanol is not 99.4% or 99.8% its all pure virgin 100%. So this is basically why we can make more power and run cooler. Hope this all makes sense..
Thanks Alot
Steven Davis
Torco Race Fuels