I'm not following this thread about running tanks dry. Without an
accurate fuel flow meter (e.g. JPI or EDI) how can you really know
how much fuel is left? Good example - flight from Denver to OSH had
me seeing 132 mph IAS and 155 mph ground speed on the GPS. But I
was also running much higher RPM than usual (almost loaded to the
brim, about 2340/2400 pounds). Great tail wind. But I also used much
more fuel than I planned for due to the higher RPM use.

(remember, my ground is 5500 ft., so I lean by default, which saves
fuel)

In the flat lands, I was unable to lean as much as I usually do,
hence the fuel usage was more than indicated even in the POH and
Lycoming manual for fuel.

Coming home, just the reverse - serious headwinds, high RPM and
more fuel used than I expected. How would knowing a more
accurate fuel capacity help? To me it seems that knowing fuel
usage is more critical than fuel capacity.

Or am I showing my ignorance again? Wouldn't be the first time...

NB: I had planned on installing either JPI or EDI fuel flow meter
this year at the annual but at this point it's a luxury and not
a safety item for me. Since my body doesn't like more than 2 hours
of flying at a time (altho I did 3+ on this past trip) I don't
worry about running out of fuel -- usually.