Surprising to me how much variability it seems in the speeds of "different" 201's. My 77' 201 is stock except for the Firewall forward HP+ conversion (10:1 compression pistons). Just returned from BWG at 9,000'. 22"/2350 rpm, operating 10-20 degrees LOP. This equates to about 55-65% power. Full fuel, two passengers, baggage, etc (120 lbs below Max Gross weight). TAS entire trip varied between 155-159 knots (averaged about 157 kts.. variable depending on up/down drafts). peak EGT 1300; peak CHT 365; OAT 14C. Fuel flow in cruise at this power setting/altitude (per fuel flow meter) varied between 7.8-8.0 gph. These are routine numbers that I have achieved over many years of flying with this plane.
Have never tried to duplicate the "201 advertised maximum speed" since I am reluctant to run it a full power/rich at low altitude to duplicate the book numbers, but I have little doubt that it would do so. (also there is a MP limitation on the STC at low altitude.. .so full-throttle below 1800' is prohibited). On shorter trips at lower altitudes and higher power settings I have routinely seen cruise speeds of 165 kts (burning >10 gph)..
I wonder if the variability in cited performance numbers reflects variations in airframe trim and drag + variations in engine tune/condition?
Just my two cents!
jon
