I've always used BP 93. I also run a cleaner every month or so for good measure. I even go as far as always using the same pump at the same station when I fill up. If someone's at that pump. I'll wait. I know it's overkill. But so what. lol.

 

Why care about detonation? Because unchecked detonation can damage or destroy an internal combustion engine. In normal combustion, the flame f ron t spreads smoothly from the spark plug across the combustion chamber. During detonation, however, the heat and pressure produced by the rising piston causes the air and fuel mixture in the cylinder to self-ignite. Instead of a smooth, progressive rise in cylinder pressure, detonation produces a shock wave that hammers internal components and produces a distinctive “knock” sound.

The higher the octane number, the more resistant a fuel is to detonation. The octane rating posted on gas pumps is an average of the Research Octane Number and the Motor Octane Number, expressed by the formula (R+M)/2. Both octane numbers are generated in a single-cylinder engine with a variable compression ratio by comparing the knock resistance of the gasoline being tested to heptane (zero octane rating) and iso-octane (100 octane number). Obviously no one tows a Super Gas car to the track with a single-cylinder engine, so the RON and MON numbers are simply indexes of a gasoline's characteristics. It's also important to note that horsepower and fuel economy are never considered in determining a fuel's octane number.


Paying extra for gasoline with a higher octane number than the engine requires is literally a waste of money. If the motor doesn't detonate on regular, then burning premium gas will not increase power or improve fuel economy. In fact, the compounds that are added to gasoline to raise its octane rating typically have less energy content than regular gasoline.

The Power Programmer plugs into the diagnostic connector under the instrument panel. This port is used by dealership technicians to access the onboard computer, and it is the gateway to reprogramming the software with the new Hypertech Power Tuning calibrations.

 

FU! I still get worse gas mileage than the damn GTO.......

 

haha... i don't get as good mileage anymore though... so next time i'll be stopping for gas too

 

Dude - I'm on your side.
I didn't say that it did anything to add any sort of performance to the car whatsoever, I just said it wouln't hurt it. I've read it does help at maximum compression, but whatever. You aren't going to get 3 mpg or 5 hp better just from switching gasses.
However, if it's something you want to do because it makes you feel like you're doing something good for your car, why not. Kinda like washing it twice a week, doesn't really *help* the car any.

 

i know... but to sum up that article, and the hundreds of others, it DOES hurt your performance... the reason being is that the gas is no fully exploding, so you're not getting the full power... it's NOT doing anything good for your car at all... that's all a myth

 

Sorry guys but higher octane gas is not dangerous for your car. And D4... that's not entirely true that it's not gonna ignite entirely. I'm a chemist and the thing I know is how molecules react. The only thing that higher octane gas does is prevent pre-detonation. If your engine is configure for 87, putting 93 in is a waste of money because you won't have any benefits. The gas will still burn, maybe not entirely but it's never gonna be bad for your engine. If it doesn't burn entirely, it's only gonna cost u more gas. Octane is a gighly flammable solvent by the way. We use that in our lab and i can assure u that it burns very easily when there a spark. The thing is that heptane burns at a lower temperature and needs less energy to ignite. When u compress a solvent that is flammable, u could ignite it without a speak or a flame because u'r tranferring it him energy. The thing is that it's harder to ignite octane by compressing it than heptane. That's why engines having higher compression ratio need higher octane gas. But it will never dammage your engine because u put 93 when you r supposed to use 87, but if you put 87 in an engine that requires 93, it could lead to knocking which can dammage your engine.

In this post, i was just wondering if it's really nessesary to use 91 or 93 in the 2.4L.

Like Dark said, maybe you're gonna be paying gas for nothing, but it's not gonna hurt your engine... that's a mth. But, Like i said, the opposite could dammage your engine.

Thanks for all the replies guys... I have to leave now...

 

i never said it would damage your engine... it's just pointless... as a chemist, you should know that

 

Answer - the Owner's manual says 87 is okay. I think it says 91 for the 2.0 s/c.