How can I tell if my car can safely use e10 unleaded petrol?
Most modern cars can use e10. e10 is a blend of 10 per cent ethanol (derived from crops - usually wheat in Australia) in 90 per cent petrol.
The ethanol is an octane booster, so e10 is likely to have an effective octane rating of 94.5 (source). So, in theory you could just about get away with it in cars that specify 95 RON premium unleaded. (That's not advice.)
The Federal Chamber of Automotive Industries (which is a fancy name for the car industry's lobby group) published a list recently of cars that can't run on e10 (usually because the materials in the fuel system can't tolerate the ethanol).
That list is here.
Alternatively, Caltex did a pretty good job sexing it up graphically and making it easier to understand at a glance.
Here is is, below. (Bear in mind the list tells you that all the vehicles specified are e10 compatible except the ones specifically listed. So if your car isn't listed below, it's good to go on e10.)