2016 manual says:
This engines is designed to meet all emissions
regulations and provide satisfactory
fuel economy and performance when using
high quality unleaded gasoline having
a posted octane number range of 87 to 89
as specified by the (R+M)/2 method. The use of 89 octane
“Plus” gasoline is recommended for optimum performance
and fuel economy.
While operating on gasoline with an octane number of
87, hearing a light knocking sound from the engine is not
a cause for concern. However, if the engine is heard
making a heavy knocking sound, see your dealer immediately.
Use of gasoline with an octane number lower
than 87 can cause engine failure and may void or not be
covered by the New Vehicle Limited Warranty.
Poor quality gasoline can cause problems such as hard
starting, stalling, and hesitations. If you experience these
symptoms, try another brand of gasoline before considering
service for the vehicle.
