Do fuel grades affect emissions? Someone told me that if my car is rated for 91 octane, then using hightest (93 octane) is too high and would create carbon buildup thereby worsening chances of passing an emissions test. Is this true? Thanks,
I would have to say that's not true at all. A higher octane fuel should actually HELP with emissions. The higher octane will clean everything it touches. Maybe not much if only used once or twice, but in the long run it definitely will help. It will help to keep the fuel lines clean for one. More importantly it will help your engine run cleaner. The higher octane level will allow the fuel to burn hotter creating a cleaner burn. The hotter burn will aid with cleaning the valves, plugs and cylinders. The hotter burn will also allow the catalytic convertor to rise in temperature which will help it operate more efficiently and burn away any passed gasses.
Whatever you do, be sure to drive the car for an extended period of time before taking it to a testing station. A short drive will not allow the engine and cat to achieve full operating temperatures, thus all sorts of waste gasses are being expelled. The longer the run, the hotter the engine and cat which equals cleaner exhaust emissions.
Thank heavens for little girls....and some of the other sizes too.