Polaris Frontier Owner's Manual page 59

Fuel
The fuel used in your Polaris engine is as important to engine life and
performance as the lubricant. Your Polaris engine is designed to run on
a minimum of 87 octane non-oxygenated or 89 octane oxygenated
pump gasoline. There's a great deal of variability in the quality of the
87 octane gasoline available across the country, so we encourage the
use of premium fuel when possible.
Using fuels with a lower than recommended octane or operating with
obstructed fuel systems will result in serious engine damage.
Always use the recommended fuels for your machine.
CAUTION
OPERATION
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