Listen, you guys go by factory recommendations and manuals and what not. I did research into this and found this simple but basic rule when it comes to gas. The lower the poorer your engine performs, the higher the better, the cumbustion is smoother and easier for you car. Of course your car could run on 87 octane or 89. I used 89 alot. The matter of the fact is that your $hit will PERFORM better. If your a cheap skate and don't want to shell out some extra change for your fuel thats fine, just dont complain if you get fuel related problems!

 

hmmm I've been running 93 since I got the car (as did the previous, original owner).... I just switched to 89 for this tank because of the damn gas prices. I refuse to go down to 87, but I think I will stick at 89 for a while.

It definately seems to rev up slower, but it runs fine on 89.... I wish I could find a place that sold 91 near me so I didn't have to put in 93.... (I don't think they sell 91 in jersey?)

 

Sorry to finally school all you panzee as#es but if you don't use the recomended fuel you are wasting money. If you buy higher grade fuels than the engine is recomended to use you are a bigger dumb ***.
Watch this highly educational video.
http://www.msnbc.msn.com/id/7924659/

 

Well, that was quite a "schooling". If anyone watched that and actually paid attention to what they're saying then it was pretty simple. It was about a majority of the "people in the U.S." don't use recommended fuel from that stated in their car manual. I don't know about you, but mine says premium. I tried all octanes and found it runs a little better on premium, but in the long run, YOU should consider the fact of engine knocking and pinging if you use LOWER OCTANE, it's a fact! The HIGHER OCTANE might pass through, not being used and in turn,.....YOU HAVE PAYED MORE MONEY TO WASTE GAS YOUR CAR DOES NOT USE! If your fine with this fact and don't care than do what you want. Don't try to coarse everyone else into doing so. BigVinnie has a point, and I support it, it's not that hard people!

 

jesus! just stick with the same **** you've been using. If it works good now, than why change it??

 

Put it like this, premium al though in cali has now been downgraded to 89 from what was originally 91. KA's still use 91 octane. There are a few model year 240's that run on 89octane due to compression and BTDC.
I have advanced my timing 4 degress through the distributor and still use 91 octane, I don't have knock and ping and I use platinum spark plugs.
Unless you have changed the ttp of the EMS, cam timing, or compression of the pistons/chamber size changing to any other octane is unnecessary.......

 

wait you said you advanced your spark timing but not the cam timing? wouldn't that cause the engine to fire before the intake valve is completly close

 

NO. You can get up to 8 degress of timing if you wanted too. You just have to upgrade your spark plugs to burn cooler. Like I said I use Platinums. If I was going to advance my timing any further I would need IRIDIUM it's that simple.
My TTP is already advanced to dump more fuel, Due to my SAFC. Like I said I use 91octane and I still don't get "KNOCK and PING".


Higher octanes "DO NOT ADD PERFORMANCE at ALL" it just slightly changes the power band to prevent knock and ping.....

Hopefully this is a lesson well learned.........

 

^ same thing i said earlier... yet people will still not listen. higher octane has nothing to do with performance or with cleaning.

detergents clean and automanufacturers decide what gas they want their cars to burn. nuff said.

 

Exactly... though higher octane gas IS needed to get higher HP without detonation after serious mods, like if you increase the compression ratio or go forced induction.