I've posted this story before but this thread seems a good time to repeat
it.

One hot afternoon in Albuquerque I was pre-flighting my Archer and noticed
that the 100LL in the fuel tester was fizzing like champagne. I showed the
fuel tester to another pilot who was also pre-flighting his homebuilt. He
in turn showed me his tester full of amber auto gas which showed no bubbling
at all. In this case, the mogas clearly had a much higher vapor pressure
than the 100LL. I chose to delay my departure until the next morning - he
fired up and flew away.

On the other hand, during a recent road trip to New Mexico, my Jeep Grand
Cherokee suffered two fuel pump failures within a week - both pumps were
brand new. The failure mode was possibly due to winter gasoline blend that
was mistakenly shipped to service stations during the hot season as a result
of the ongoing shortfall in US gasoline stocks. Winter gas has a big load
of volatile components to aid cold starting but will boil and vapor lock in
the summer. In my case, the volatile fuel likely caused the in-tank fuel
pump to cavitate, overheat and fail.

The service writers in both dealerships who replaced the bad pumps told me
that they had been inundated with fuel pump failures and otherwise
unexplained hot stalling.

Diesels are sounding better all the time.

Bill Daniels