See also:

Fuel requirements
Your new vehicle is designed to use only unleaded fuel having a pump octane number ((R+M)/2) of 87 (Research Octane Number 91) or higher. Your new vehicle is designed to obtain maximum performanc ...

Fuel requirements
unleaded fuel having a pump octane number ((R+M)/2) of 87 (Research Octane Number 91) or higher. Your new vehicle is designed to obtain maximum performance with UNLEADED FUEL, as well as minimize ...

POWER AND FUEL-ECONOMY ARE UP TO PAR
That description might have you thinking the Optima has all sorts of power. True, the upgraded 2.4-liter four-cylinder gets added power for ’09 with 175hp and 169 ft-lbs of torque, but it’s no ...