Anyone that runs unleaded petrol in their aircraft should be aware of the potential for unexpected results...
There is not an 'Avgas' equivalent quality control system in the standard of forecourt unleaded petrol. One can see all sorts of additives cleaners and 'enhancers' advertised these days. Unleaded petrol seems to smell 'different' these days also - maybe I am imagining it - anyone else notice this? I have come across a few stations in Ireland that advertise 10% ethanol in their 95 octane unleaded... Several reasons why this is not good for a light aircraft:
1. Higher vapour pressure means bubbles can form in fuel lines and pumps when you don't expect it to - eg low pressure warm days - esp at high altitude.
2. More heat required to vapourise ethanol means increased likelihood of carb icing..
3. Ethanol might not be good for some of the components of your fuel system - think about rubber component of the engine - driven fuel pump, seals, any non-metal pipes etc...
The regs are there as a result of years of hard lessons... stick to them...
Don't fly above 6000 ft on unleaded 'car' petrol (mogas)
Don't allow mogas in tanks to get above 20 Deg C
Don't use fuel with ethanol (there is an easy test.. look it up in the links below)
If you have 2 tanks think about using Avgas for take-off and landing and switch to the cheap stuff in the cruise.
Read about mogas and ethanol in general on these websites:
UK position here
Irish position here
http://www.iaa.ie/index.jsp?&1n=93&2n=1 ... =185&a=493
aeronautical notice here:
Good US site and source of most of the mods here:
http://www.autofuelstc.com/autofuelstc/ ... ation.html
Smoke me a kipper, I'll be back for breakfast.