I have a 92 gsr completely untouched in showroom quality and in my car manual and on the gas lid it states to use premium fuel (93) only. I get great gas mileage but I am curious what the possible side effects are if I use lower octane fuel. Paying over 4$ a gallon is getting annoying, does anyone know if I can use regular octane?

 

?

 

It could damage the motor and you'll actually get worse MPG. Just pay the 15 cents extra per gallon lol. You could use 91, which is the highest we have in CA.

 

Why change, I have a 1997 GS-R and since I bought it I put 93 octane only in it like it's required to have. I really don't think the extra $3.00 to $5.00 is going to hurt your pocket.

I would say you would get shitty performance and lower gas mileage if you use lower octane gas.

 

I pay at the MOST an extra $3 to fill up my tank with premium over regular 87 octane. 3 fill-ups a month, that's a whole $9 extra a month to run the correct fuel vs. regular crap. It's really not THAT much more.

When you consider that at most stations, the most difference in price between regular and premium is 30 cents (many are still only 20 cents higher), the percentage difference is MUCH lower than 15 years ago when gas was $1.10 and the difference was still 20 cents for regular to premium. Back then premium was nearly 20% more than regular. Nowadays it's only 5% to 10% more.

 

I think you should quit being cheap and pay the extra 10 dollars a month for premium...I use to think the same way when I bought my first GSR...I thought, "man, I gotta pump premium now....That is going to crush me!!!" I avg 30 +/- 2 MPG.

Look at it this way:

Taken from my Kwik Trip down the street from my house
regular now: 3.74
Premium now: 3.94

10 gallons of regular = 37.xx
10 gallons of premium = 39.xx

$2 that you are going to cry over? SRSLY????

I drive 60 miles everyday, I pump 10 gallons every week. 4 weeks in a month. and extra 8 dollars every month....$96 a year for premium. You can do it.

 

I agree. My car is currently tuned for 93 (military in SC and now stationed in 29 Palms) and unfortunately 91 is all I get get here in CA. I havent had any pinging but I baby the **** out of it until I can get a chance to retune it on a dyno. So yea, definetly stick with the highest when the car is designed for it, especially a performance model like a GSR. Any standard vehicle, the higher octane will actually hurt the engine. The spark isnt hot enough to completely burn the fuel.
On the other hand, you get what you pay for. If you go to the local Choke-N-Puke, there is a chance that their 91(93) is actually 87. I have known crappy gas stations to fill all of their tanks with the low grade and sell it for higher. It's illegal, but that doesnt stop a criminal.
And we all know not to get gas while or directly after the tanker fills the tanks....debris is all over the place inside.
Sorry for the rant....kinda boring in the middle of Afghanistan.