problem... when i first got my car.. i think it was filled with premium gas.. i think the dealer filled it with premium not sure though... at my first fill up... i filled it up with plus... meaning the second most expensive gas type... the car has been fine for the first 3/4 of the tank... but at the last fourth... sometimes when i come to turn on the car... it makes the coughing noise that cars usually make to turn on and i dont think its a good noise.. I could just be paranoid and this happens to all the cars.. but sometimes it sounds bad and i am worried... anyone experience this??? any suggestions of what i should do.. plz help..

http://www.cardomain.com/member_page...page_id=321439

 

Start putting premium - that's the recommended octain for this car.

 

Actually, the coupe requires 91 octane. The manual says you can put 87 in if you have to, but only put in enough to get you somewhere where you can immediately fill up with 91 or better.

The sedan is supposed to be able to handle 87 for extended durations, but 91 is recommended for performance and efficiency.

BTW, you're not saving any money on these cars by using cheaper gas. The anti-knock sensors retard timing to compensate for the lower octane, and you wind up lowering your power and fuel economy. The savings of the lower grade gas is offset by the loss of fuel economy. And, in your case, possibly by engine damage if you keep running it with those strange noises.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

maybe the gas-station you last filled up at is cheating... i would fill premium right away if i were you

<font color=green>-Ramb0</font color=green>

 

Why didn't you fill it up with premium? After paying $35k+ for a car I just don't understand how people can't pay an extra few bucks at the gas pump for the fuel grade the car requires.

 

Word.

 

Maybe I misread the pump? here in Chicago, but I could have sworn premium was 93 octane, not 91. Oh well. All I know is it cost $32 to fill up my tank. Can you say, "ouch"?

 

Give the G a treat and fill up with Super Premium. I think you'll see the 'coughing' will go away. From then on use 91 octane or better for best performance. [img]/w3timages/icons/smile.gif[/img]

<font color=red>GSM</font color=red>

 

The premium level of octane depends on your location in the USA. Different regions use different mixes of gasoline now.

 

At our pumps up here in Canada, it shows the octane of the fuel. Reg=87, Mid=89, Prem=91, Super Pr.=92,93,94.
Do your pumps show the same? And is super prem. available only in certain areas of the U.S.? Thanks.[img]/w3timages/icons/smile.gif[/img]

<font color=red>GSM</font color=red>

 

The pumps all show the octane on a yellow sticker. Federal law.

I've never seen it called "super premium" but in some places I think you'll find Reg=89, Mid=91, Plus=92/93. I think there are still some backwoods places where Reg=85.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

I have seen some gas stations in L.A. that have reg as 85 mid as 89 and plus as 91-93. I just fill the car up with the most expesive gas there is like the dealer said.

 

I have a gas station in my town that sells 87, 89, and 93 octane. Since I really only need 91 octane, could I fill a tank half full of 89 and half full of 93 to result in an average of 89 octane? Is the octane ratings based on a linear function such that this could be done?

G35 Coupe/Silver/Graphite/6MT/Prem.Pkg./BSM - now (maybe) May delivery.

Doug.

 

Yeh bro you can mix half and half. I've done that too. [img]/w3timages/icons/smile.gif[/img]

<font color=red>GSM</font color=red>

 

No, half a tank of 89 plus half a tank of 93 will give you 91, not 89. [img]/w3timages/icons/smile.gif[/img]

Yes, you can mix it up that way.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter