2012 Rio EX Sedan UVO Auto/Tanzanite blue/tinted windows/Vent visors
Hi, I searched on this forum for the topic. Not too many answers and some contradictory views. Too make a short story. Last time, I fueled up with Supreme 91 octane from Ultramar -I'm in Canada- their only gas that is ethanol free. Before, I fueled with regular 87 with 10% ethanol as is recommended in Rio owner manual. Usual mileage would be 7.2 - 7.8 L/100km with more or less 480 km on the counter when the yello light ignites. Now the counter shows 470 km and the needle is next to last in the second half of the gas gage. So I expect this trio to be in the 500+. I swear I did not change driving habits. Slow starts, slow breaking, foot off the gas pedal as soon as I can, 90-100 km/h on highway, some times Max AC on -BTW I'm happy to notice there's not a great loss a power when AC is on-, sometimes power sunroof opened. Eco on. So is it the placebo effect or I see my Rio EX Sedan Auto getting better mileage with Supreme than with ordinary? Plus, it "seems" peppier. Not by much but I can feel it too. At each fill up, I change Eco setting: On/Off. When Eco off, I get 3-5 miles mpg less (do my mileage in both Liters/100km and MPG). Last fill up driving Eco Off, I even got 7 miles less. Question: will using Super 91 octane gas all the time will affect the engine like it will act bizarre if I decide to fill back with regular? Is using the middle grade gas Plus with 89 octane and 5% ethanol would be a wiser choice. Or go back to regular and forget about this tirade against using 91 octane gas in a Rio.