Fuel probes

I have read that capacitive fuel probes will cause variations (errors) when using auto fuel. I plan to use both auto and avgas. Does anybody know how large this error is? Is perhaps a bowl type more preferable?

I got an answer from Laimers at the Stratomaster Yoahoo group. I paste the answer here also, in case someone is interested.

It depends heavily on the dialectric constant of the fuel.
This is unfortunately heavily influenced by alcohol/methanol blended
fuels and other additives which have become popular in automotive
fuels. Unfortunatley, the composition tends to vary dramatically
between fuel brands, seasons and other reasons.
The effect this can have on capacitive fuel probes is dramatic -
rendering them useless.
BWM South Africa some time ago had to retrofit a new series of cars
with normal fuel level senders (they had capacitive probes) after
motorists got stranded due to incorrect fuel level readings.

Rainier

Click to expand...

In Europe we can only be sure that auto fuel is in accordance to spec EN-228 (close equivelent to ASTM D-4814 in the US), but those standard does not specify anything else but sulphur content, corrosion inhibition properties, oxydation properties etc. meaning the exact composition and additives can vary greatly.

All in all, capacitive probe and auto fuel is a no-go.

Capacitive Fuel Probes

Everything posted about capacitive probes are correct.
But the one really huge variance in these probes that was NOT mentioned is WATER!
Water will cause some very erratic readings. Usually showing FULL even when the tank is empty except for enough moisture to coat the pick-up. And the coating can be ONLY moisture, as in condensation.

I work with capacitive fuel sensors in big rigs using diesel. And YES even different diesels from across the country wil cause different fuel level readings.

REMEMBER MoGas now has ALCOHOL and alcohol is hydroscopic. It does not take much water absorbed into our MoGas to cause a capacitive probe to go erratic.

Who was the DUMB AHOLE that voted for Methanol in our MoGas? Take him...Take them all out and shoot them!
NO WAY is it better for the enviroment!
Shooting them is!

Barry