89CivicDX1.5 - Question on fuel

Is it Ok to switch in between high octane unleaded (98) gas, and the regular unleaded gas? Would it harm the engine or fuel system?

No but there is no point in doing so..it wont run better at all.

Thanks FrodoGT; I know that. I will be doing this only to prepare it to pass the emission test in Toronto, Canada.

Nope, wont hurt it a bit.

running on to high of an octane of gas can cause drivability problems. not saying it will but i have seen it a couple of times. if the car isnt in need of it, i.e stock there really is no point, it may run worse on it actually an produce more emissions. anyway where do you get 98 octane anyway i have never seen it, all i have seen is 86,87,89,90,92, and 110, it wont harm anything most likely though. dont really see it helping to much though. is your car burning oil or something to make you assume you wont pass?

the best thing you could do is a basic tune up, plugs, wires, cap and rotor and air filter would help you way more than running higher octane gas ecpecially if you dont have an upgraded ingnition system, or running a high compression app. or possibly even some sea foam, or something along the lines of a BG injector and manifold cleaning. i have used the BG system on all of my cars and noticed a huge diffrence in how the car ran and the emmisions it put out, i dont rember the number anymore as its been a while but before and after reading on the 5 gas analyzer where pretty dramatic.

we dont have emmisons here in minnesota, (thank you jesse ventura) and thats a great thing as none of my cars would pass.