I don't believe there is a such thing as a leaded fuel engine. All gasoline is unleaded, some just a higher grade.
It depends what you mean by 'better'. Lead used to be added to gasoline to stop pre-ignition or detonation (which causes engine knock or 'pinking') but it was found to have very bad side effects environmentally and physiologically. most countries have banned the use of leaded gasolines, and modern gasoline have other ways of dealing with detonation. so i guess, unless you like bad air and bad health, unleaded is best.
No, leaded gasoline is not a heterogeneous mixture. It is actually a homogeneous mixture where the lead additive is uniformly distributed throughout the gasoline.
To find leaded gasoline you would have to be off North America so I don't think this should ever happen, its been banned for decades
Older gasoline used to contain chemicals such as tetra-ethyl lead. This prevented preignition in the engine and allowed engines to be higher compression. They stopped using it because of heath and environmental issues. Different additives are used in todays car fuels instead. Leaded fuel can still be used in offroad equipment and airplanes.
Leaded fuel is a type of gasoline that contains tetraethyllead (TEL), a chemical additive used to boost octane ratings and prevent engine knock in older vehicles. However, leaded fuel is now largely phased out due to the harmful effects of lead emissions on human health and the environment.
In addition to the hydrocarbons present in normal gasoline, leaded gasoline contains tetra-ethyl lead or other lead alkyls for their anti-knock effect.
I don't think there is a way to visually tell the difference between leaded and unleaded fuel. However, leaded gasoline has become "extinct" and it is more likely that you have unleaded gasoline in the can.
It takes unleaded I think
Leaded gasoline was banned in the US in 1996 up until now. This was implemented through the Clean Air Act of 1996.
A gasoline with an octane of 110. Most of the time - leaded. In a racing engine this allows you to make significantly more power.
Yes, it is unleaded. No gasoline sold for consumer vehicles in leaded.