Here are some fuel flow figures for my TB20
6000ft +5C QNH1036 23/2400
GPH(US) / IAS(KT)
10 125
10.5 135
11 138
11.5 144
12 147
12.5 148
13 150
14 150
Flowmeter error: better than 1% (checked after test flight)
ASI error: approx 1kt (measured by 3-heading GPS method)
Peak EGT around 11.5GPH.
Weight: approx 10% under MTOW i.e. 1260kg.
Hard to beat.