ok, my '04 has about 15K miles on it and I've started to notice a pinging when I strain the engine. It usually happens when I accelerate hard up-hill. I always use 89 octane and have changed the oil every 3500 miles. Should I try a couple of tanks of premium before taking it to the dealer?

 

yes premium

 

93 Is The Answer. Same Thing Happend To Me. And That Solved The Problem..

 

With our '04 we started out running 87 as the dealer said that would be fine when asked. Started to knock after a few tanks so we went to 93 - problem solved. I told the hubby we should try to use 89 and split the difference on cost. The car actually ran WORSE on 89 than it did on 87. Moral of that story - we are sticking with the 93 if at all possible.

Definately try it before you assume there is a problem. It should only take a tank maybe 2 to get an idea.

 

Never put anything but 93 in my G. Try it, you and your G will like it.

 

it is definitely worth using premium. the difference in cost from reg to premium or even mid grade to premium is prob a few bucks a tank anyway. the ping will go away in a few tanks.

 

The car requires premium gas, it says it right on the gas door.

 

Could be weak gas, or timing advanced somehow. Try some premium for a while. If that doesn't work, have the dealer check you timing and adjust.
C.

 

Um, NO. At least for the 04, the owner's manual specifically states that 87 is acceptable, but 89/91 is recommended.

 

If it's pinging at all then the knock sensor isn't doing its job. Take it to the dealer. Apparently there are many cases of rodents eating through the wiring for the knock sensor or something ridiculous like that, based on the material the wiring is made from being particularly tasty.

(OK I re-read that and I SWEAR I'm not insane. Do a google search)

 

Okay, let’s set the record straight… On the ‘04 sedan (at least mine) the inside filler door says “Premium fuel recommended for maximum performance”.

The owner’s manual (attached) says: 87 AKI (Anti-Knock Index) – Research Octane Number 91.

As always, the higher the octane the better… My question is: If you own one of the highest rated performance sedans (in many cases THE highest rated), why would you put sh!tty fuel in it?

 

Wow, learn somethin' new everyday. Didn't know the difference between AKI and Research Octanes - heck, didn't even know there WERE different octances:

http://www.eric-gorr.com/techarticle...erminology.htm

-Chris

 

Because it's like batteries, light bulbs and several other things in life - if the less expensive is no better than the expensive stuff then there is no way I am paying more for it. I'm cheap pure and simple. I like my money and I see no reason to spend the extra when it doesn't make a difference. Note my original reply that we have tried them all and have found what makes a difference in our car - so we will use it. Now I will also say that with no other vehicle I have owned has it made an ounce of difference. In those cases I think it is quite ridiculous to pay the extra for no extra benefit. Our family spends over $200 a month on gas with the cheap stuff and only one full time driver. That few dollars a tank adds up. IMHO - more money for no improvement = lack of thought BUT more money for notable improvement = reasonable.

FYI -

Anti Knock Index or AKI - The octane number you see at the pumps in the US equal to (R+M) /2 . This is the average of two octane numbers; the Research Octane Number (RON) and the Motor Octane Number (MON) .

Octane Number - A measure of the anti-knock characteristics of a given fuel. The octane number you see at the pumps is the average of two octane numbers; the Research Octane Number (RON) and the Motor Octane Number (MON). This number is sometimes referred to as the Anti Knock Index or AKI. Each of these octane numbers is determined by ASTM laboratory tests. Low-speed and low load knock characteristics are determined by the RON test method. The MON method tests high-speed, high load, high temperature situations, in practice these conditions exist during periods of high speed power accelerations, hill climbing, or any period of high power output (sounds like racing to me). Obviously the MON number will be lower, but it's the one racers should concern themselves with.

Anyone explain any difference between these two terms? Looks like the same to me.

 

you got to be a fool to use 89 gas in this car..NO **** its gona run like crap!...i can tell the difference sometimes when i end up with a bad tank of gas from a junkie gas station....the car runs like CRAP... "oh should i use premium"...really? you think so? no way?

 

The post that I was responding to stated that "The car requires premium gas, it says it right on the gas door." I corrected him, pointing out that the *manual* stated otherwise. By your own quote, the fuel door "recomends". A recommendation, no matter how strong, is NOT a requirement.

As my wife has stated, we started out with 87. We now use 93 exclusively in both Gs.

[RANT]
I have seen the same sentiment many times in other threads on this forum. Statements to the effect that people shouldn't buy an expensive performance vehicle if they plan on using cheaper fuel. I consider statements like these to be the utter height of arrogance. Some people might have purchased the car for other reasons. Others may have purchased the car in one financial state, but may have had to cut back on amenities; in such situations this might include the more expensive gas, regardless of its combustion properties.

I admit I sometimes ask similar questions. Why buy a four-wheel-drive SUV if you never plan on going off-road? Why buy a nice high-end stereo receiver only to cripple it with crappy speakers? Why buy a new high-def TV and connect it to your cable box using cheap composite cables? You know what?
First, It's none of my business. Second, to suppose that I can question someone else's financial decisions is pure folly.
[/RANT]