Ram Trucks 2015 3500 - Owner Manual - Manual (Page 643)

performance. The use of premium gasoline (Over 89
octane) is not recommended, as it will not provide any
benefit over regular gasoline in these engines.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Poor quality gasoline can cause problems such
as hard starting, stalling, and hesitations. If you experi-
ence these symptoms, try another brand of gasoline
before considering service for the vehicle.
Over 40 auto manufacturer’s world wide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) which define fuel properties
necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasolines that meet the WWFC speci-
fications, if they are available.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline.”
Reformulated gasoline contain oxygenates and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
The use of reformulated gasoline is recommended. Prop-
erly blended reformulated gasoline will provide im-
proved performance and durability of engine and fuel
system components.
Gasoline/Oxygenate Blends
Some fuel suppliers blend unleaded gasoline with oxy-
genates such as ethanol.
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