Honda Car Forum

I know it's recommended but can you just you mid grade, or even regular unleaded?

I would stick with what they recommend otherwise you're screwing with the car and it will not perform at its greatest!!!

use cheaper unleaded save you money

Nope, you have to stick with premium. Its a civic, gas should not be an issue for you.

Try the regular unleaded and see what happens, if the. engine knocks, you can have it retuned to burn reular unleaded

What year? Newer cars have the ability to use lesser grades, as the ecu will automatically retard the timing to reduce detonation (aka knocking or pinging).No harm in trying mid or regular, just pay more attention to the sound of your engine and switch back if you hear noticeable knocking. If its an older Si, i would guess pre-96, you can manually retard the timing.

Honda and Acura ask that you use the gas STATED in the manual and on the GAS cap door...it's PREMIUM. Use it or make a mess of your engine.If you can't pay for the gas...don't buy the car.

I have a 2000 civic Si and I use the reg. feels the same too me.

in some states due to elevation you can use mid-plus gas, but if your not in one of those states you have to use premium unless you want to ruin your car. here i use mid-plus on my rsx type-s, the dealership even said it would not be a problem for the engine, and again fine because of the elevation of where i live.

How much do you like your motor. Do you like detonation? Its says premium for a reason. Your engine is designed for it. its not recommended...its required. Poor drivability Less power worse gas mileage detonation (which leads to sever engine damage) failed emissions(ive seen it muliple times and if vehicles fail emissions what does that tell you?) need i say more? You act like the hundreds of engineers flipped a coin on what fuel sticker they would put on the fuel door.