These are some answers I got from snow perf regarding the max-mpg package they sell (similar to the stage 3 i think). I haven't done it yet but will be soon.
You can download the manual with instructions for install from snowperfs website (good manual) the time to install is going to depend on you, the tools you have etc.
----- answers i got from Greg Dunn, Director of Operations at Snow Performance ----
The system doesn’t inject 100% of the time, and it varies the amount that is injected through the 175ml/min nozzle – just like your fuel injectors have a certain capacity, at idle, they aren’t delivering full injection volume.
A 7 gallon reservoir should last about a tank to two tanks of diesel fuel under light driving. Under towing conditions when we are using the 175 plus the 375 or 625 (or all three if you are making big power) the tank should still last about a tank of diesel, except that your diesel mileage and therefore range is likewise reduced.
Concerns about pooling/quenching – not at all. If the system is set up correctly, so that it doesn’t overinject (our instructions and techs can help you start out right in the ballpark) you won’t have problems at any other time. I wouldn’t jump on the throttle in the first 5 sec of operation, but it won’t hurt anything. If the engine is running, there is more than enough heat and pressure in the combustion chamber to consume water-methanol. We are getting 20-70 micron droplets for atomization – unless something is terribly incorrect in the installation, those droplets won’t puddle or drop out of suspension, etc.
You will benefit in terms of MPG without your foot in it as well as in it – with this understanding: your mileage will be better driving easy or hard, than it was without the injection. If you could do a whole tank at full throttle without the water-methanol and then one with the water-methanol, you would see a large improvement in mileage overall, even though it would be a huge drop from light-throttle mileage. That is essentially the situation when we are injecting while towing – much greater load and injection volumes, larger percentage increase in mileage (2mpg increase at 10mpg is greater % than 2mpg at 18mpg)
It does include the temp probe with the system, as well as the tap for the injector nozzles and the probe (at least on the newest kits we are shipping have the correct tap for both applications).