Low Octane or High Octane premium? Petrol, Gasoline
Nov 15, 2020 23:12:12 GMT -5
timpa136 likes this
Post by wayne on Nov 15, 2020 23:12:12 GMT -5
The bike was designed to run on what we'd call today, low octane fuels. Back in the day, unleaded gas in Australia was probably 89 RON (known as "regular").
Generally speaking, higher RON fuels are formulated for high compression engines. Something the RE5 is not.
So burning any higher octane fuel than your garden variety "regular" is probably doing nothing more than burning your $$.
I've only heard one decent argument for running 98 and it comes from the owner of an established Mazda race shop. He gave me a rundown on Australian fuels from production, importation and delivery. What he said boiled down to this: Our Australian 91 fuels are not QC'd as well as the 98. Even after delivery to the local garage, you can't be sure what you're getting. For example, he claimed that any service station that needed to dispose of some "junk" fuel (left over diesel included) would do so by pouring it all into the 91 tank.
He said that any reports he gets of inconsistent running in customer's rotary cars he usually resolves by telling them to switch to 98. It's a far more consistent fuel here in AU.
So up to you. But the bike is designed for low Octanes.
For a bit of fun (yes, I call this fun, don't invite me to your party), I did a Google maps measured 100.0 klm loop involving freeway, twisty climbs and moderate speed backroads. I did it with a tank of 98 followed by a tank of 91. Everything else was essentially the same. Time of day, weather, warm up, speeds etc. Fuel use was measured by filling up at home using precise measuring containers (Cattle grade! No less).
With 98, the bike used 6.58 litres. With 91, it used 6.54.
Less than one hundreth of bugger all difference. I've heard said that after filling up with 98 ".....my RE5 was lifting it's front wheel on acceleration". Hmmmm...... if it was making noticeably more power with the 98, it would be burning noticeably less fuel. It isn't.
For MY bike, it felt a tiny bit happier with the 91. But who knows, could have been the way the wind was blowing........
Generally speaking, higher RON fuels are formulated for high compression engines. Something the RE5 is not.
So burning any higher octane fuel than your garden variety "regular" is probably doing nothing more than burning your $$.
I've only heard one decent argument for running 98 and it comes from the owner of an established Mazda race shop. He gave me a rundown on Australian fuels from production, importation and delivery. What he said boiled down to this: Our Australian 91 fuels are not QC'd as well as the 98. Even after delivery to the local garage, you can't be sure what you're getting. For example, he claimed that any service station that needed to dispose of some "junk" fuel (left over diesel included) would do so by pouring it all into the 91 tank.
He said that any reports he gets of inconsistent running in customer's rotary cars he usually resolves by telling them to switch to 98. It's a far more consistent fuel here in AU.
So up to you. But the bike is designed for low Octanes.
For a bit of fun (yes, I call this fun, don't invite me to your party), I did a Google maps measured 100.0 klm loop involving freeway, twisty climbs and moderate speed backroads. I did it with a tank of 98 followed by a tank of 91. Everything else was essentially the same. Time of day, weather, warm up, speeds etc. Fuel use was measured by filling up at home using precise measuring containers (Cattle grade! No less).
With 98, the bike used 6.58 litres. With 91, it used 6.54.
Less than one hundreth of bugger all difference. I've heard said that after filling up with 98 ".....my RE5 was lifting it's front wheel on acceleration". Hmmmm...... if it was making noticeably more power with the 98, it would be burning noticeably less fuel. It isn't.
For MY bike, it felt a tiny bit happier with the 91. But who knows, could have been the way the wind was blowing........
