Sorting by Octane
 

I'd like to sort my fill-ups by octane level, as I'm comparing performance over time. Can this be enabled as an option? (Apologies if I'm posting in the wrong place.)

Looking for something similar. I used to record all my mileage and fill-ups in Excel and had formulas that listed cost per mile based on how much you paid per gallon for the previous tank and current odometer reading. It helped narrow down which brand and octane was most efficient for a given vehicle, in my case a 1987 Honda CRX Si. There's mild debate that running premium octane (93) in a vehicle that only "needs" regular (87) is a waste of money and yields no obvious benefit(s), but I found that higher rated gasoline improved mileage based purely on pump numbers.

I have done similar and found that I experienced smoother running and improved mpg using "Premium" petrol in my 1.2 litre Jazz/Fit. However, the 5% improvement in mpg was overshadowed by the 10% increase in price. Here in the UK "Premium" petrol comes at a "premium". Supermarkets, in the main, only sell "Regular", and if you want "Premium" you have to buy from a branded outlet, where even their "Regular" is more expensive.

Seen improvement with higher octane also, but it was a turbo charged engine designed for higher octane. GM just labeled it regular gas for marketing. The fuel economy improvement wasn't worth the price increase, unless I mixed my own midgrade, but that wasn't worth the hassle.

Without the higher effective compression ratios, you won't be able to take advantage of the higher octane. That said, there are other factors in play that could explain fuel economy improvement in using premium in a low compression engine. My first thought is that premium gas tends to have better detergents added. Cleaning out the fuel system will improve things.

Then cars advance ignition until knocking is detected, and then back off slightly. This cycle is constantly repeated. With octane higher than what the engine can fully use, ignition timing advances as far as possible. This could mean better fuel economy and performance as the max point for the car is likely beyond what it runs at with regular. Then the engine should run smoother as it isn't always on the cusp of knocking noticable to you.