so ive been wondering... i got a stock 03 lancer oz and ive been pouring in the different gas octanes...tryin to see what works best

anyone know which octane is preferred and what works best and why to pour it...

i mean other then the $$$...

 

I use 93... Don't need too, but it SEEMS a little faster/smoother running it.

 

Use the lowest possible (in this case 87). Putting in higher octane is useless, if the car isn't programmed to use it you're just wasting money and potentially harming the car in terms of deposits and cat damage.

 

High compression. 93 baby.

 

wait...so regular engine...u recommend 87?!?!

another thing...i poured 89 a couple of times....

and now my engine seems like its skipping or something...even though its not could that be y?

 

Yes.

 

there really shouldn't be anything wrong with running higher octane than needed... As long as you don't run lower than needed you should be fine.

 

As I said earlier running higher octane than needed can actually damage the car as well it simply being a massive waste of money. The car was tuned to run 87 octane, why put in anything else?

 

I used to run 93 octane because my logic was that nothing but the best for my baby. Well, on 93 I ran a 15.5 and 15.7 bone stock. Because of rising gas prices, I switched to 87. Not only did I get the same or better gas mileage (now getting about 26 - 28 mpg versus the 24 - 26 mpg before, but my commute has changed) but my 1/4 mile times are virtually the same. No power increase or decrease, no timing skip no nothing.

So running 93 octane is a waste of time and money unless you are using some form of forced induction or running high compression pistons.

 

all octane is, is plain and simply the gasolines resistance to knocking. The higher you run the less chance of pre detonation. I know with my SAFC-Neo they recommend running higher octane for running leaner AFR's. That is why I run 93 octane due to me running 12.8-13.2 AFR. I could probably get by with mid-grade but I play it safe.

 

Yes that resistance is achieved by changing the mixture slightly. If a car isn't set up to deal with the octane, it's just a waste.

 

I also agree its a waste running higher octane unless your car needs it. And of course, it is true, running higher than necessary can hurt your engine. newer cars today, unless specified otherwise, should only run 87. I was switching around betyween 89 and 93 (I have piggy back from rrm). I didn't notice any difference at all between the two - so I just stick with the 89 now. Interestingly enough (I know others have said the same) with all my mods, and then having to run higher octane fuel, I am pretty sure I'm getting BETTER gas milage than I used to. That would seem to make sense, the piggyback basically leans out the mixture, and the few basic mods I have are only increasing hp, so I figure less gass + more power = more mpg?

 

I've heard that if you have the RRM PB and used higher octane that ur going to get more mpg

 

I run 93 because I'm boosted. 87 is fine for non-turbo/ normal compression engines though.

99% of people with stock cars that say 93 runs better are suffering from "It is more expensive, it MUST be better!" syndrome. 93 octane actually bruns slower than 87, therefore unless you have high compression, 93 doesn't help you at all.

 

i have a RRM-tuned piggyback which is set up for 93. i run 93 and it runs fine. i don't even look at the price anymore. not like i have an option to not pay it or anything.