Leaning With Egt Gage - Cessna 172R Pilot Operating Handbook

Figure 4-3. Cruise Performance Table
LEANING WITH AN EGT GAGE
The exhaust gas temperature (EGT) may be used as an aid for
mixture leaning in cruising flight at 80% power or less. To adjust the
mixture, using this indicator, lean to establish the peak EGT as a
reference point, enrichen the mixture by the desired increment
based on Figure 4-4, EGT Table.
Figure 4-4. EGT Table
As noted in this table, operation at peak egt provides the best
fuel economy. This results in approximately 4% greater range than
shown in this handbook accompanied by approximately a 3 knot
decrease in speed.
Under some conditions, engine roughness nnay occur while
operating at peak EGT. In this case, operate at the Recommended
Lean mixture. Any change in altitude or throttle position will require
a recheck of EGT indication
ALTITUDE
80% POWER
70% POWER 60% POWER
KTAS NMPG
KTAS
NMPG KTAS
NMPG
Sea Level
113 12.3 108
13.4
100
14.5
4000 feet
117
12.8
111
13.9
103
14.9
8000 feet 122
13.3 115 14.3
105
15.3
MIXTURE DESCRIPTION
EXHAUST GAS
TEMPERATURE
RECOMMENDED LEAN
(Pilot's Operating Handbook )
50° Rich of Peak EGT
BEST ECONOMY
Peak EGT
SECTION 4
CESSNA
NORMAL PROCEDURES
MODEL 172R
4-26
Dec 2/96