It's a question I hear occasionally: Is it a bad idea to apply gasoline with a higher octane rating than the manufacturer's recommendation?

The brusk answer to this question is a simple "No." Mod  motorcycle  engines  are designed to run just fine using gasoline with a higher octane than recommended. If your owners' transmission call s  for a mini mum of 89 octane, you'll be OK  using 91 octane gasoline.

Having A Gas:

Excavation deeper, this question often arises over a misconception over what an octane rating really is. I've had this discussion with people who think higher-octane gas "has more energy" or "is cleaner."

Some petroleum companies do sell loftier-octane gasoline with additives that supposedly help your engine burn more cleanly, only this has nothing to do with octan e rating—information technology's simply an upselling technique.

An octane number is a rating of how much compression the gasoline tin handle before igniting. Higher octane ratings mean the fuel is less likely to pre -ignite under loftier force per unit area.

Here's what that means  for a motorcyclist. Take an boilerplate motorbike, like my Suzuki DR650SE.  In standard form, information technology's a fairly low-pinch engine. It's designed that way so it volition work with a wide variety of fuels, and considering reliability was more important to the designers than performance. Low -octane gasoline was fine for this stock engine.

A couple of years ago, I installed a high-compression piston, which raises the pressure of the combustion chamber. At present, under certain circumstances, low-octane fuel will pre-ignite  (some motorcyclists phone call this "detonation"). The engine'due south pinch causes low-octane  fuel to spontaneously combust before the spark plug ignites the fuel. This results in a "pinging" sound, and if I were to ride around similar this for a while, I could damage my engine .  T he pre-ignition means  my engine is now firing out-of-time.

High-octane gasoline is formulated to resist pre-ignition, thanks to chemic additives and other voodoo that takes place at an oil refinery.  When I run 93 octane gasoline in my DR650, I have no pre-ignition. When I run 89 octane , I might have a problem.

Motorcycle engines with loftier compression from the factory will typically require high-octane fuel. For instance, late-model BMW take chances bikes require college-octane gasoline, unless you've had them re-programmed by a dealer. Some owners do this, because loftier-octane gasoline might not be available while traveling in remote areas.  Running low-octane gasoline could cause pre-ignition, and be a problem in these bikes. Running gasoline that's higher-octane than manufacturer spec will be OK.

If your motorbike's manufacturer does not recommend high-octane fuel, there's no guaranteed advantage to running it. Some owners may claim there's a departure in fuel economy or horsepower, simply these claims are usuall y based on seat-of-the-pants observations, non any sort of scientific comparison.

Zac Kurylyk