SamFromTX

Octane methodology calculation differs between US and Europe. Our 91 is closer to their 95 and 93 to 98-100

ShakeNBake

I am not sure what you are saying exactly. What is your point? It has next generation R-comps and the grip is fantastic as a result, and largely why the stopping and skidpad times are extraordinary. It's common sense. I am happy it has them, since there is no other track tires available for that size - people tracking it should be happy.

For reference, here is a comparison of tires showing how much impact they can have on skidpad times:

http://www.caranddriver.com/features...-a-911-feature

MM3.9GT3

Thanks for posting the article. As for the Octane of gasoline, it is a common misconception that Europe has "better" gas. You do have a valid point about 91 Octane in California. Most of the other States have 93 Octane. Even then, it would most likely lower the trap speed by only 1 MPH to 125 MPH. That is damn fast.

Absoutely correct. Europe uses RON (Research Octane Number), while the U.S. uses the formula (RON + MON) / 2, where MON is the Motor Octane Number. There is a 4 to 5 point differential between RON and the U. S. measurement.

Mike in CA

First, the acceleration numbers speak for themselves. No way to claim an unfair advantage there relative to other cars; the 991 GT3 is just damn fast and it's engine is clearly underrated at 475HP. As to skidpad and braking figures, other than guessing, there's no way to quantify how much of the improvement is due to tires and how much is due to improved brakes, chassis upgrades, RWS, etc.

Every time a new car comes out with the next generation of tires and other upgrades one could claim that's it's not fair to compare the new to the old. Whatever. The new package is what it is, and as a soon-to-be owner the fact that these numbers pretty much blow away all of my most optimistic expectations is all I really care about.

Serge944

But then again, Porsches only lose 7% through the drivetrain while many others are 10-15%. In any other car, it would be 500hp.

The RS 4.0 trapped 122mph in R&T's testing with 494hp, and that is without the advantage of the latest generation tires, sophisticated launch computers, and lighting fast PDK shifts:

http://www.roadandtrack.com/cm/roada...S_4.0_data.pdf

Mike in CA

I live close to Sonoma Raceway and will blend a few gallons of 100 unleaded with our crap CA 91 to bring the octane up to 93 for track events. I also store a few 5 gallon containers of 100 for the same purpose.

For the street, as you suggest, losing a couple mph off my 1/4 mile trap speed is irrelevant.

Dan39

Funny, I have often thought that GT3s are not loud enough at the track. When the parts become available, I'll be deleting the side mufflers...

911dev

The main photo of the red car with ceramics at that angle looks killa!

You must be very excited Mike.

wanna911

A somewhat underrated motor seems likely given that trap speed. A 500 hp C6Z weighing about the same traps about that speed, so it makes sense. And yes, the tires do seem sticky given the launching for a RWD car and the braking power, either are only as good as the tires under them, especially with RWD.

Not hating, just stating the probability. Still fast either way.

Remove RWS and add Manual and I would do nasty things with a car capable of 126 mph traps. That's higher than my 600 hp TT trapped.

MM3.9GT3

Great point.

Sonnen Porsche

I am aware of the different octane ratings. 100 octane in Germany is equal to 95 octane here.

http://www.pinux-products.com/octane-rating/

Generally, octane ratings are higher in Europe than they are in North America and most other parts of the world. This is especially true when comparing the lowest available octane level in each country. In many parts of Europe, 95 RON (90-91 AKI) is the minimum available standard, with 97/98 being higher specification (being called Super Unleaded). In Germany, big suppliers like Shell or Aral offer 100 octane gasoline (Shell V-Power, Aral Ultimate) at almost every gas station. In Australia, “regular” unleaded fuel is RON 91, “premium” unleaded with RON 95 is widely available, and RON 98 fuel is also reasonably common. Shell sells RON 100 petrol from a small number of service stations, most of which are located in capital cities. In Malaysia, the “regular” unleaded fuel is RON92, “premium” fuel is rated at RON97 and Shell’s V-Power at RON99. In other countries “regular” unleaded gasoline, when available, is sometimes as low as 85 RON (still with the more regular fuel - 95 - and premium around 98 available). In Russia and CIS countries 80 RON (76 MON) is the minimum available and the standard.

It should be noted that this higher rating seen in Europe is an artifact of a different underlying measuring procedure. 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, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the “regular” gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as “regular”, equivalent to 90-91 US (R+M)/2, and deliver 98 (RON), 99 or 100 (RON) labeled as Super Unleaded.

Manifold

These blistering performance numbers continue to raise the question in my mind of the proper use of this car. IMO it's pointlessly fast for road use, like at a stallion confined in a small yard. At the track, it will easily 'win' in every DE run group if the driver is at least average for the run group. That means that in higher run groups, driving it at least 8/10ths will mean a blistering pace, with the associated risks, need for skill, and need for real safety equipment (6-pts, possibly halos, roll bar, cage would be preferable but impractical for street use).

Mike in CA

I am, Chris. Despite the hefty surcharge for the ceramics, I feel really good about my decision on them and on color. I know I would have second guessed myself forever if I didn't get PCCB's and that alone is worth the $9200.

What did you finally decide, or have you decided yet?

Serge944

I mean, sure, you don't need anything more than a 1.6 liter diesel for street use... ...and plenty people enjoy a spec miata on track.

But that's not why we're here.

Mike in CA

I get your point. OTOH, there are any number of cars out there that are pointlessly fast for street use. One thing that I've taken from a number of the reviews, as well as from my friend who has driven the car extensively, is that the 991 GT3 has a dual nature that allows it to be enjoyed at reasonably sane speeds. Still, it will be frustrating at times not to be able to unleash it's potential. Maybe I should move to Germany.....