Nah. The earliest were 25 hp, but went to 36 hp in '54 or '55. By '61 they had a blistering 40 hp, which would make my
Ghia do 82 mph, which is where it cruised all the time. Bugs typically would do 72 mph on a 40 hp, and a 40hp bus would hit
the governor at about 57 mph. Not all had govs and many were removed. A '63 bus at top speed of maybe 65 was a bit
terrifying in any wind at all.
By '67 they had 53 hp 1500 cc, and a bug would hit 77 mph, showing the futility of getting
higher speed via hp, and in the Squarbacks with the dual carbs, 66 rompin', stompn' hp!
But 3 HP added to a 40 or 53 hp bug would be noticeable.
As far as high octane fuel....my brother's '60 (36 hp) ran out of gas one day (no gas gauge,
had a reserve lever like a bike) and we were far from home. Had a quart of Coleman fuel, and
it got us to the next station, about 12 miles. No idea what the octane of Coleman fuel was
but a 36 hp had something like a 6:1 compression ratio, so wasn't too picky.
Bill