991 GT3 MPG
11-20-2013, 11:38 PM
#46
I think the lower gear ratios are a big part of the mileage issue, especially the shorter 7th gear. Also, I don't believe that PDK is inherently that much (if at all) more efficient than a MT, but it earns it's high mileage EPA numbers in the Carrera because of it's default short shifting auto ECO-mode (which the GT3 doesn't have) and because of Start-Stop (also not on the GT3).
DFI makes a difference, but it's offset by the fact that the 991 GT3 squeezes out 40+ more horsepower than it's same-displacement predecessor. More power comes at a price.
All that said, I think in the real world, the new car will at least match, and perhaps exceed the old one, FWIW, which isn't a whole lot....
DFI makes a difference, but it's offset by the fact that the 991 GT3 squeezes out 40+ more horsepower than it's same-displacement predecessor. More power comes at a price.
All that said, I think in the real world, the new car will at least match, and perhaps exceed the old one, FWIW, which isn't a whole lot....
We should be seeing a net benefit in MPG from DFI combined with higher efficiency of the PDK and better drag coefficient of the car, less drivetrain parasitic loss due to EPS, etc.
Instead we are not, and I'm pretty sure the 40 HP is just coming from spinning the rotating assembly to 9k (since horsepower is a function of torque, just spin her higher, add ignition timing and you get more HP--grossly generally speaking).
So what gives? I'm with the OP. I don't get it.
11-21-2013, 12:58 AM
#49
Drifting
Agate does look good. In the color poll thread I voted for it at the time. Saw it on a new 991 and was slightly underwhelmed, but still a very nice color and I could have been happy with it.
Thing is, it's hard to find a color that doesn't look good on this car. Every time I see a different one I think, "hey, maybe I should have ordered that...."
Thing is, it's hard to find a color that doesn't look good on this car. Every time I see a different one I think, "hey, maybe I should have ordered that...."
11-21-2013, 01:46 AM
#51
Rennlist Member
But all that 40+ horsepower just comes at higher revs, doesn't it?
We should be seeing a net benefit in MPG from DFI combined with higher efficiency of the PDK and better drag coefficient of the car, less drivetrain parasitic loss due to EPS, etc.
Instead we are not, and I'm pretty sure the 40 HP is just coming from spinning the rotating assembly to 9k (since horsepower is a function of torque, just spin her higher, add ignition timing and you get more HP--grossly generally speaking).
So what gives? I'm with the OP. I don't get it.
We should be seeing a net benefit in MPG from DFI combined with higher efficiency of the PDK and better drag coefficient of the car, less drivetrain parasitic loss due to EPS, etc.
Instead we are not, and I'm pretty sure the 40 HP is just coming from spinning the rotating assembly to 9k (since horsepower is a function of torque, just spin her higher, add ignition timing and you get more HP--grossly generally speaking).
So what gives? I'm with the OP. I don't get it.
Firstly the figures quotes by the OP are incorrect....
P.S. Gas mileage may vary according to the quality of fuel used for the test. For example in Europe the car is rated on 98 RON in USA on I am not sure but maybe 91 MON?
11-21-2013, 02:12 AM
#52
Rennlist Member
If used on a track as intended, the fuel economy sky rockets to 40+ litres/100km so fuel economy and GT3 don't belong in the same sentence or paragraph for that matter! 
11-21-2013, 08:55 AM
#53
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Don't blame the OP: http://www.porsche.com/usa/models/91...gt3/#techspecs
Last edited by Nizer; 11-21-2013 at 10:22 AM.
11-21-2013, 09:09 AM
#54
Nordschleife Master
11-21-2013, 11:36 AM
#55
Actually, that is most definitely not true. They simulate aero drag on the dyno by adding drag/resistance that is a function of speed. The process is pretty sophisticated.....engineers involved, etc.
11-21-2013, 01:31 PM
#56
Who cares? Someone asked what kind of gas mileage my 599 got. I just looked at them, like are you kidding? I just said bad. LOL.
11-21-2013, 04:29 PM
#59
Electronic power steering removes parasitic loss from an engine, therefore should result in more efficiency. Same goes with drag coefficients, the PDK efficiency and so on.
It's just curious that the 991 GT3 has all these things over a 997 that an engineer would think causes better MPG as a byproduct, but clearly the contrary has occurred.
11-21-2013, 04:54 PM
#60
Rennlist Member
I don't think anyone in the thread is discussing this from a frugal or eco-concern context; more from an engineering standpoint.
Electronic power steering removes parasitic loss from an engine, therefore should result in more efficiency. Same goes with drag coefficients, the PDK efficiency and so on.
It's just curious that the 991 GT3 has all these things over a 997 that an engineer would think causes better MPG as a byproduct, but clearly the contrary has occurred.
Electronic power steering removes parasitic loss from an engine, therefore should result in more efficiency. Same goes with drag coefficients, the PDK efficiency and so on.
It's just curious that the 991 GT3 has all these things over a 997 that an engineer would think causes better MPG as a byproduct, but clearly the contrary has occurred.
The 991 GT3 is more fuel efficient than the outgoing 997.2 GT3 even though it is 35kg heavier, almost 40 bhp more powerful and has more torque (7lbft).
The TUV & EC approved factory published figures state this, the european motor testers reviews state this and its in the 991 Gt3 handbook/manual.
Your stateside EPA and gas guzzler tax boys have either made a mistake or your fuel is less efficient to burn.
Im not sure why we are even discussing this point as its a mistake at the USA end I expect...or the USA are measuring efficiency different than the car manufacturers in Europe...