on my GSR it says PREMIUM GASOLINE ONLY, but damn, gas price right now is just killing me, i drive on the freeway alot, usually 40 miles a day (CA that's why), so i've been thinking of filling up the tank with cheaper gas, can some1 tell me the cons of using 87 or 89, is it really that gad? cuz i've been using premium 91.

 

You've got a GSR. A decently high compression, thats why its suggested that you run premium gas. I run 93 octane in my geezer, I wouldn't suggest going to 87 or 89 but im sure some would say it wouldn't hurt. I guess its safe to say..."how much do you care about your car"?

I'd stay running 91 octane and dish out the extra cents for it. Or buy a cardboard box with wheels and rock that on the way to work.

 

dont half *** it and put 87 in it. i know here in tx 93 is only 20 cents more a gallon so if you think about it your only paying like 2.50 more to fill up.

 

i look at it like preventative maintenance- you spend a little money now to save your engine down the road, no pun intended

 

doesn't the higher octane prevent detonation from occuring in a high compression motor like the gsr's b18c, thereby protecting your motor.
just pay for the higher octane, and then drive very gingerly so it sips gas.......drive it like you were driving ms. daisy.....keeping out of vtec.
sucks, but you save gas

 

You live in LA not Denver. Don't do it if you care about your car.

 

I would consult my owner's manual and go with the recommended octane they suggest. Also be careful with ethanol, and methanol blends which may cause damage to some aluminum alloy parts. Consult your owners manual for details on this. When in doubt go with pure gaslone.

If your owner's manual recommends the 93 then stay with it. If the engine has high compression the high octane is a requirement to prevent pre-ignition or engine knocking, which could seriously damage your engine. I have seen people throw a rod through the block or put a hole in a piston because they "low balled it" on the type of octane in the gas they were using. I believe the rule of thumb is above 10:1 compression you need the 91-93 octane and 8.5:1 or lower you can do with 87. Be aware of the risks if you decide to experiment. If you hear excessive knocking or pinging switch back IMMEDIATELY to 93.