Can I mix gas of different octane ratings to get desired octane rating?
no doesn’t work that way but you can try this stop at place you always stop at fill with highest octane set mileage write it down drive til you need to refill at same place use next lower octane and one that gets you best mileage right one to use at that place then you drive up street to next place do the same thing and you find one there that gets you best mileage then you know two places two types and then do same thing with two or more places coming back home not all fuels are the same and not all cars need high octane and most are just recommend octanes you use what gets you the best mileage an donly way of knowing that is to test a few brands and a few octanes i know my car gets great mileage with shell high octane but gets same with mobil regular and i know my truck doesnt like to run on either one of them but gets great mileage with chevron or BP only one who can tell you is your self only way to know it is by testing a few brands alwaysd start with highest octane set mileage wr
