i have a 97 honda civic es, with a cold air intake, and a catback exhaust. no performance mods beyond that. if i want my car to last and run well, and the engine inside to be clean, whhere should i gas up, and what octane rating should i use?

 

87 octaneor whatever isstated in the manual. Avoid places like citgo, speedway, etc. Mobil, BP, Shell are all great

 

anything more than 89 octane in your car is a waste of money. You could run some VPower from Shell, but the only benefit would be from a "cleaning" aspect.

 

I run 91 octane and gas up at chevron... so idk its seems like i get a little more power with the 91 octane.

 

my tuner swears by exxon.....i personally run cheap gas from sheetzin my dd an exxon in my toy.

 

For some reason my car doesn't like Shell's gasoline that well since i got my turbo[&:]

 

Higher octane actually lowers your power output

 

definatly the cheapest gas in my car. as long as its 87 octane (jeep), or whatever is recommended in the manual for your own car

i never noticed much diference in any gas, its mostly in peoples head [8D]and they think there is a difference.

fuel pumps have screens, and cars have fuel filters for a reason so if there is anything in the gas it won't clog an injector.

running cheap gas has NEVER caused a problem in any car i have ever owned.

 

http://en.wikipedia.org/wiki/Octane_rating

"The power output of an engine depends on the energy content of its fuel, and this bears no simple relationship to the octane rating. A common understanding that may apply in only limited circumstances amongst petrol consumers is that adding a higher octane fuel to a vehicle's engine will increase its performance and/or lessen its fuel consumption; this may be false under most conditions — while engines perform best when using fuel with the octane rating for which they were designed and any increase in performance by using a fuel with a different octane rating is minimal or even imaginary, unless there are carbon hotspots, fuel injector clogging or other conditions that may cause a lean situation that can cause knocking that are more common in high mileage vehicles, which would cause modern cars to retard timing thus leading to a loss of both responsiveness and fuel economy. This also does not apply to turbocharged vehicles, which may be allowed to run greater advance in certain circumstances due to external temperatures.

Using high octane fuel for an engine makes a difference when the engine is producing its maximum power or when under a high load such as climbing a large hill or carrying excessive weight. This will occur when the intake manifold has no air restriction and is running at minimum vacuum. Depending on the engine design, this particular circumstance can be anywhere along the RPM range, but is usually easy to pinpoint if you can examine a printout of the power output (torque values) of an engine. On a typical high-revving motorcycle engine, for example, the maximum power occurs at a point where the movements of the intake and exhaust valves are timed in such a way to maximize the compression loading of the cylinder; although the piston is already rising at the time the intake valve closes, the forward speed of the charge coming into the cylinder is high enough to continue to load the air-fuel mixture in."



If you don't want to bother reading most of the above, the short of it is: on a modern, well-maintained car, higher octanes will make little or no difference.

I guess if you're going to be running WOT for long periods of time or you're going to be driving with a heavy load, higher octane gas might prevent detonation. Any car with a knock sensor should be able to detect this and retard your timing appropriately to prevent this, though. If your car is old enough to not have a knock sensor, then maybe you should tune up your car if you're worried about these conditions