Forced landings would have to get your attention I'm guessing...

 

The density and lead content are two major issues. The other issue is that 100LL has a high level of aromatics which cause many to complain about slow throttle response.

Note: the "Low Lead" is named that as it's compared to AVGAS 100/GAS(contains 4grams of lead per gallon!). The low lead namce on 100LL can be misleading as it still has plenty of lead in it to destroy your cat and o2.