1999 Civic Si (Vtec?), Is Hi-Octane Really Required?
 

Im driving a 1999 Honda Civic Si (non-vtec) and I was wondering if Hi-Octane is really required. I been reading all over the place that hi-octane gas has no difference than regular gas (only that it takes more energy to combust) And is just costing me extra money. I suppose I could just do regular fuel treatments to compensate. So what do you guys think. Also, When Driving long distances (between montreal and toronto for example) Which is better on gas: Doing 100 on Cruise Control or doing 140 on Cruise control

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

there is no 99 Si non vtec

do you mean Si SOHC? (I see you're in Canada)
if you have the D16Y8 engine you only need 87

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

Well since you are in Canada i am assuming that your Si isn't the B16 SI and is actually the USDM EX model With the D16Y8, Our SiR is actually thei USDM Si... and so in turn you only have to run 87 octane and not high octane. Just like MXS said

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

Well I bought a 99 Civic Si Recently And I dont see any V-TEC labelling on the engine itself or outside on the body so I assume naturally "Dang its not a V-TEC", Still happy with my car. So my car doesn't have V-tec right?

Yes I am in canada

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

You would need to buy SiR if you want DOHC VTEC, you have Si which will be a SOHC VTEC. It wont be labled on the car, and im pretty sure the D16Y series wont say it on the valve cover even if it is, but i could be wrong about that.

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

no... you're right about that. It won't have any labeling on the car or anything

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

^ Thanks
So, there you go man, you got it straight now

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

Is there a Huge Difference between HP and Acel time between stock SOHC and the DOHC Vtec?

Well, in my car it isnt labbelled anywhere VTEC but it is a 99 Civic Si which I bought off a Honda dealership and people are saying that all 99 Civic Si's are VTEC so thats good news for me :)

I dont got much money Right now so Im going to do little things to my Car like Use some STP fuel Injector cleaner in the gas. Buy some quality Spark plugs (Can you suggest what model type I should look for when buying for my engine type, probably going to canadian tire). Im thinking that ill put a Strut bar in the front and probably under the rear of the car (will I notice better Handling in the winter?). Also my car vibrates when I am stops/Idleing, what Can I do to stop that, I think it might also be that muffler tip I recently put on...

Also Im going to start using regular gas(Regular is 87 :D http://www.petro-canada.ca/eng/prodserv/fuels/6815.htm) for my 99 Civic Si unless someone else advises me against it

What other little things under the 40$ CDN Range can you guys suggest I can do to my car for better fuel economy and better car performance :).

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

1. HP difference- yes your motor is D16Y8 (127hp), B16 ranges 158-168
2. Like we said, it wont be labeled, but it is VTEC
3. Spark plugs-just ask for 99 civic si, since your si is the above mentioned D16Y8, thats what they should give you plugs for
4. Vibration-more details/a muffler "tip" would not cause a car to shake
5. 87 octane is fine you dont have any performance parts

RE: 1999 Civic Si (non Vtec) Is Hi-Octane Really Required?
 

And yes there is a big difference between "regular" and "premium" gas. It's the octane rating, when you are running higher compression or boost, you need a higher octane rating to avoid detonation.

But on a stock civic, you would see no difference.