We purchased a 2008 Civic SI yesterday. It has 16,000 miles on it. I have read different answers on other sites as to whether or not you really have to use premium gas. I have searched this site for the answer and haven't found it. Do you have to use premium gasoline for the civic si?

Thanks.

 

yes, use premium.

check "Required Fuel" at http://automobiles.honda.com/civic-s...fications.aspx if you don't believe me.

 

Yes Honda recommends that you use 91 or higher octane in the Si.

If you do use lower octane fuel it's not the end of the world the ECU will back off timing and you will be fine but just won't have as much power.

 

But, using the lower octane won't physically hurt the engine or do any damage?

Thanks again for your help.

 

Owners manual?

 

Is spending 30 cents more a gallon really that important to you? Just use what Honda reccommends and be done with it. Lower octane gas will not cause problems but your engine will not perform how it is meant to perform.

 

Stick with premium, its not much more money and this car is good on gas. I use 91 from shell and haven't be disappointed.

I don't know if it is bad to use 87 but i'm not about to try given how much the car costs.

 

as everyone else has said, stay with 91

 

The post about the ECU adjusting the timing to compensate for lower octane gas is true. But keep in mind that this is not an instantaneous process... you run the risk of pre-detonation with just a single fill up of regular gas. Also, since the engine was tuned from factory for 91+ octane, you'll also notice a dip in your fuel mileage if you don't use premium.

Based on Honda's specs for the car... even if premium is $0.45 more than regular, it'll only cost you an extra 6 bucks or less per fill up. Easier to monitor your driving habits and usage than to risk the possible negative side effects.

You might run the car on regular for years and never experience any problems. Me personally, i wouldnt risk it.

 

30 cents more? No way. Its like 10 cents more expensive.

I never understood why people buy an SI, and then complain about needing premium fuel. That's why regular Civics exist.

 

Well the price difference varies depending on state. Premium here is almost 25 cents more than regular. It used to be 10 cents between grades, but that's still a 20 cent increase over regular.

 

Me too, higher performance cars run on better fuel. Very simple.

Also, where I live, Premium is around 15-20 cents more per litre (Southern Ontario). So it does vary on the state and country!

 

who cares? Spending 6$ or 7$ more a tank isn't going to kill anyone's wallet, and it is much better for the car.

 

If you want to cheap out on the fuel, you should have bought an lx, and I'm not trying to be a dick about this.

 

premium.

 

I always considered 91 octane mid grade fuel since every gas station I've ever been too has 93 octane as their top grad fuel. So I would only say the 91 octane mid grade that is recommended is only 10 to 15 cents more per gallon. And the 93 octane is around 30 cents more per gallon.

The pumps around here always say 87, 91, 93.

 

We have 87, 89, 93 out here.

Occasionally they'll have 87, 89, 91, 93.

 

About the male private part part too. LOL


That is why I bought an EX. Regular rules!!!

 

Your fuel is low! We get 95 as standard in UK - our premium is 97 / 99

 

It's not rated on the same scale.

Fuel in the UK is rated by RON. Fuel in the US is rated by an average of RON and MON.

95 RON is roughly equivalent to 91 (ROM+MON)/2. 98 RON is roughly equivalent to 94 (R+M)/2.

 

Wow I don't get 93 here...the top is 94 at Sonoco but I'm a much bigger fan of Shell 91 V-power.

91 is premium, 94 is "ultra"

 

94? I've never seen that before.

 

Thanks for all your help. I'm not trying to cheap out and it isn't going to kill me to paying the extra $3.00 or whatever. I was just wondering based on different things I had read. We didn't know it was premium until I read the boards. We will definitely put premium into it

 

Good to hear. Good luck.

 

X2