Did anyone notice the article about the 997 GT3 in the newest (August) issue of Excellence?

Page 66, last paragraph at the bottom:

"The Bosch Motronic engine management has been mapped to suit, with more agressive ignition timing than before. The GT3 is designed to run on Europe's 95-octane fuel, but Porsche admits that optimum performance requires Europe's 98-octane gas. With the right fuel, the GT3's numbers are spectacular: 415bhp at 7600rpm...."

So, the big queston is: if the engine is designed for 95 octane, and 98 octane is required to get 415hp (aka "optimum performance") out of the engine, what happens when the GT3 is run on USA's 91 octane fuel?

You have to figure the Motronic will react to the lower octane by re-mapping the fuel & ignition curves, same as any other car. How much power does it give up?

Funny how all the articles advertise the 415hp number, but kind of leave out the little detail that that only happens on Europe's 98 octane fuel !!

Another interesting side note about the 997 GT3 cup car:
According to a Road & Track article, the cup car will be using the 996 GT3 engine, not the new "997 GT3 street
engine".
They don't go into the specifics as to why.....

 

Damm wtf, Europe gets the best out of each car dammit

 

I believe that Europe's octane levels are rated differently than ours, so I wouldn't be too alarmed by this.

 

glad i don't need to drive them daily. i feed them 100 octane or mixed it all the time. just 7 bucks a gallon though.

 

Yes, I believe our 95 is similiar to your 91 octane.

I agree, euro spec cars are a bit "better" then US spec ones. And you don't even get all the cars over there because of all your regulations etc (GT3 RS, M3 CSL for example) . But considering we pay more for our cars, you should be very, very happy.

 

. But considering we pay more for our cars, you should be very, very happy.[/quote]

WE pay MUCH more i will say

 

A quick search on the internet:

Octane rating

The most important characteristic of gasoline is its Research Octane Number (RON) or octane rating, which is a measure of how resistant gasoline is to premature detonation (knocking). It is measured relative to a mixture of 2,2,4-trimethylpentane (an octane) and n-heptane. So an 87-octane gasoline has the same knock resistance as a mixture of 87% isooctane and 13% n-heptane.
There is another type of Octane, called "Motor Octane Number" (MON), which is a better measure of how the fuel behaves when under load. Its definition is also based on the mixture of isooctane and n-heptane that has the same performance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON. In most countries (including all of Europe and Australia) the 'headline' octane that would be shown on the pump is the RON: but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the "roaD Octane Number" or DON, or (R+M)/2. Because of the 10 point difference noted above this means that the octane in the United States will be about 5 points lower than the same fuel elsewhere: 87 octane fuel, the "normal" gasoline in the US and Canada, would be 92 in Europe.


So I can buy 94 Octane here in Michigan so I guess it would be the equivalent of 99 Octane in Europe.

 

Because we build em

 

Honestly, if you take notice of the different gas ratings USA gets equally good if not greater fuel than we do.

 

Ahh.... I thought our RON-MON/2 calculation was only a couple of points off whatever method Europe was currently using.

IE: CA 91 octane would be equivalent to about 93 or so in Europe.

Maybe all's well!!

 

correct. Euro's 98 Octane rating closely approximates the US 93 octane rating. It is true for those that live in CA will have slightly muted performance due to the crap 91 offered....

 

Ahh good to hear lol, we have some good 93 here in NY, shell v power baby

 

93 is the norm in Dallas but we have some pumps that offer 96!

 

A local 76 station in OC has 100 octane.$$

 

-The 997 GT3 cup car has the same engine like the 996 only 10hp increase cause of the seq. gearbox and some changes to the internals.


-You guys get a Turbo for the money we only get a C2S Cab.


cheers