Piper ARCHER II Pilot Operating Handbook page 197

Petersen Aviation, inc.
984 K Road
Minden, NE 68949 -
1.
Limitations Section:
Fuel: Unleaded or Leaded Automotive Gasoline
91 minimum antiknock index, and 93UL {RON+MON)/2 per
ASTM D-439 or 0-4814, and EN228 (minimum 98 RON).
Also approved for UL91 (D-7547 and UL94 {D-7592)
Intermixing with UL91, 93UL, UL94 & 100LL also approved
DU NOT USE FUEL CONTAINING ALCOHOL
Fuel Management:
When operating on auto gas, including when auto gas is intermixed
with aviation gasoline:
Placards:
1. Part No. V674903-28, Item 12/24-9 on the instrument Panel in full
view of the pilot:
TAKEOFF AND
LANDING ON RIGHT
TANK WHEN OPERATING
WITH AUTO GAS.