How can I get better gas mileage for my car?

Can you use octane booster to get better gas mileage in your car?

• For a bunch of years, we've been getting gas at the pump that had 5% alcohol in it and didn't even know it. Now over the past few years, the ratio has jumped to 10% - but they did warn us with stickers on the pumps. That ratio tends to make a lot of cars trigger a false computer code that turns on the "service engine" light. It also causes a drop in MPG because alcohol has less explosive power than regular gasoline, therefore causes more fuel to be burned. Just ask someone with a flex fuel vehicle what MPG they get with E85 - it's about half hat they get with 90% gasoline. I have been using 100% gas when I can find it, because my cars get about 10% better mileage. I now hear that the 100% won't be available after year end, which has been confirmed by my local 100% station. My question is whether I can add an octane booster to 90% gas and get better mileage like I do with 100% gas. Has anyone tried that? What would you suggest?

• Answer:

  My car is designed to take in 87octane (regular) and I have read a lot of websites that upping up your octane does nothing to benefit performance or fuel mileage. Though last summer I noticed pinging whenever I press on the throttle hard, so I upped my gas to 89(midgrade). That got rid of the pinging, but I also noticed I could go 580km until the gas icon flashes rather than before around 500km before the gas icon flashes. Either the gas station is not being honest of the octane level or maybe there is a certain octane level where it is beneficial of it becoming a little higher. As for me I'll keep it on midgrade because it seems it's the best balance for my car ATM.