Octane Question [Archive] - SaabCentral Forums

: Octane Question


Fogcutter
23rd September 2003, 09:24 PM
Sorry if this has come up before, but I have a friend who tells me that the octane amount makes no performance difference in the car. I have been dilligently keeping 91 octane premium fuel in my 02 Aero since day one. The dealer said it was vital. Can someone please clarify if there really is a difference between 87 and 91 octane, and quantify it?

Thanks,
Martin

geekpryde
23rd September 2003, 09:27 PM
I would also like some info on this quesiton. I was told to use premium by the dealer as well, and I seem to "feel" the difference when regular is used, but even Consumer Reports says that using anything other than "regular" is a waste of money. Has anyone done a side by side comparison to the performance boost with premium versus regular?

JCarpio
24th September 2003, 08:35 AM
Premium gasoline is lower in sulfur content which helps the life of your catalytic, although the Mobil premium gas seems to cause the "rotten egg smell".

I've found Shell and BP work pretty well.

The performance difference that I've noticed is most noticeable on hot days the regular gas seemed to cause acceleration hesitation/stumble and the engine would ping if pushed to hard. According to my manual it says regular gas can be used if premium is not available, but basically that the engine management system is designed for higher octane. The additive packages are different between a regular, silver or a premium gasoline.

I also, noticed that my fuel economy drops (highway or city) if regular gas is used. With premium I normally get 31mpg on the highway and 20mpg in the city.

Good luck...

Krafty
24th September 2003, 09:10 AM
I'm not sure if my performance was different, but I could definately tell when I used 87 octane. I had a tremendous amount of pinging and knocking under medium to hard acceleration that went away with higher octane fuels. I'm definately using the good stuff on mine.

WASAAB
15th October 2003, 01:44 AM
Sorry if this has come up before, but I have a friend who tells me that the octane amount makes no performance difference in the car. I have been dilligently keeping 91 octane premium fuel in my 02 Aero since day one. The dealer said it was vital. Can someone please clarify if there really is a difference between 87 and 91 octane, and quantify it?

Thanks,
Martin91 octane got more additives than the 87..
Think it as synthetic and conventional oils..
91 got more additives that are good for your engine..well as burns easier to get you more( Little more ) power..
F1 don't use 87..they got something over 100 octanes.. :P

DrBoost
25th January 2004, 03:07 PM
Hi !

Let's say that you're driving a 9-5 Aero, the good fuel is a MUST if you want all the power that you paid for when you bought the car.

This is why:
Higher octane rating menas that the fuel is more resistant to knocking. IF the engine is knocking, then the engine management will reduce the power, this is to protect the engine. So, I'm using 98 RON (that's the best pump gas we have here in Sweden) in our 9-5 Aero (and 9000 B234R+).
Let's say that I go to Germany where the have 100 RON at the gas stations, will there be any performance improvement ?
Well, IF the engine ran without knocking the answer is NO, if it's hot weather, then the engine is more prone to knock. Burning 100 RON will help the situation, resulting is MORE POWER and IMPROVED FUEL CONSUMPTION.

If, however, the car runs fine with 98 RON, no knock, the filling up with 100 RON is a waste of money.

Higher octane rating does not mean "more energy", often it's actually the oter way around.... Surprised ?
Well, I would guess so....