Drive your car at around 20mph, put it in 3rd gear and push down on the gas, If the engine starts to make a pinging noise, stop this and put some higher octane in it, If it doesn't ping continue using the cheaper gas.
Low octane fuel (87) is like racing gas, it ignites much easier than higher octane fuel (93) . Putting 93 octane in a car that uses 87 octane will make the car run worse.
Low octane fuel (87) is like racing gas, it ignites much easier than higher octane fuel (93) . Putting 93 octane in a car that uses 87 octane will make the car run worse.