Will Using 87 Octane impact performance?

[IdahoMtnSpyder]

I just took another look at my gas numbers from June 1 to September 31 for both 2016 and 2017. Both summers were similar driving habits and conditions. In 2016 I rode 8171 miles and used 275.81 gallons of 91 octane. In 2017 I rode 8155 miles and used 274.92 gallons of 87 octane. So, for 2016 I had 29.625 MPG on 91 and for 2017 I had 29.663 MPG on 87. 87 octane gave me 0.0375 better MPG! That was a whopping 0.13% improvement! Virtually all of the gas was ethanol based.

Ron's numbers are for a 998 engine and mine for a 1330 engine. I think engine design is a factor in why Ron, and other 998 owners, have experienced better mileage with 91 octane.

[Peter Aawen]

.....

Ron's numbers are for a 998 engine and mine for a 1330 engine. I think engine design is a factor in why Ron, and other 998 owners, have experienced better mileage with 91 octane.

There is that!


The 998 engines are designed and tuned as high revving high performance engines with a fairly tight (& high) power band in a wide rev range, peaking well up into the 8000's; while the 1330 engines are designed and tuned as slower revving high torque engines with a pretty wide & flattish torque band in a shorter rev range, peaking in the 5,000's.... I can't recall if there's any difference between the two in compression ratio as well, and I'm not anywhere near a ready source of that info, but I suspect there'll be some difference... With any luck, someone here will be able to chime in & tell us all what the compression ratios are and if there's any significant difference?!

Still, given the above it's not all that surprising that the 998 engine's notice the difference in octane rating more than the 1330's - high revving high performance engines and their 'higher/tighter' state of tune generally means that they are more critically reactive to any changes in the things that let them work at their best; while slower revving 'lazier' engines tend to run a less critical/more forgiving state of tune and so are far more tolerant of any variations in any/all of the variables like octane rating, altitude, fuel temperature, ambient temperature etc...

Just Sayin'

[Snoking1127]

I just took another look at my gas numbers from June 1 to September 31 for both 2016 and 2017. Both summers were similar driving habits and conditions. In 2016 I rode 8171 miles and used 275.81 gallons of 91 octane. In 2017 I rode 8155 miles and used 274.92 gallons of 87 octane. So, for 2016 I had 29.625 MPG on 91 and for 2017 I had 29.663 MPG on 87. 87 octane gave me 0.0375 better MPG! That was a whopping 0.13% improvement! Virtually all of the gas was ethanol based.

Ron's numbers are for a 998 engine and mine for a 1330 engine. I think engine design is a factor in why Ron, and other 998 owners, have experienced better mileage with 91 octane.

??? I average 34 MPG +/- tenths regularly with 87 octane. And I like jacket rabbit starts and going vroom vroom, and when not doing that I run on CC.