Methanol evaporating from the mix?
 

I find myself having to top up the W.I. bottle even when I haven't used the car. It could be 50cc after a week of inactivity (garaged).
I'm using the stock windscreen washer bottle, and the water tube feeding the aquamist pump has a tight-fitting grommet and silicon as well.

I suspect that it's the methanol content evaporating, but it could just be my paranoia. :?

Anyone else have the same problem?

the reduced surface tension of water-MeOH mixture and azeotropic effects will accelerate evaporation. Get a hydrometer between the range of 0.8 to 1 S.G. (specific gravity) to see if you are loosing just methanol or methanol/water.

Hadn't thought of that, I use a Spec C boot mounted tank (12 litres) for my setup which uses a 50% water/methanol mix, haven't notived any loss but brimmed its nearer 14 litres so difficult to tell.

bob

Good idea! :smile: