I have a good ol' B16 PV544 with a 6 volt system and 4-speed gearbox.

Does anyone kow their current city/highway mileage with the unleaded fuels and original valve seats?

Also, has anyone replaced their valve seats and found an increase or decrease in fuel mileage? If so, what is your new city/highway mileage?

I'm asking because I'm doing a mileage project and I'm collecting data to compile with what I have come up with and eventually obtain an average. Please let me know.

When I was driving one of those the mileage ran from about 26-30
on the highway. I agree with John, type of valve seats don't affect
mileage, although their condition will. If you drive conservatively
at a fairly constant speed your mileage can be better.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

True enough. I was getting around 28-30 mpg on my worn out old B-18 when it was freshly tuned. Not that a tune-up lasted more than about 3 weeks with the old carbs, valves, etc.....
--
'64 PVMoneypit, '93 945 Turbo

Valve seats would have no effect on mileage unless the old ones were burnt and worn and leaking badly.

Mileage varies wildly with engine condition, speed driven, driving style, terrain, weather, etc, etc, etc.

I could tell you the mileage I get in my PV but I never check it and mine is far from stock.

I am getting an average 20 mpg on B16 with dual carbs, during the first 450 miles on rebuilt engine. Most driving has been short trips and engine rarely even gets warmed up, so I expect better on longer trips.
HJ