Does anybody know why the EPA mileage ratings dropped so much from one generation to the next? Was it a change in the testing procedure, or some feature that changed? I don’t think it was the engine or transmission changes. One is not significant enough and the other should have changed it the other way.

 

same top speed .. more gears .. i'm assuming the gears are shorter?

 

Interesting. That's quite a change; if anything I'd expect the 8 speed to have slightly better mileage. My guess is EPA changed how they calculate the mpg.

 

Got curious so I looked up my car -- the 2017 911 GTS is rated at 18 and 26.

 

wow that's a lot lower!

 

This may be the reason (below). The EPA methodology for calculating MPG changed in 2017. I suspect that the 991.2 MPG's were calculated on a '17 model built in '16.

https://www.fueleconomy.gov/feg/ratings.shtml

 

That is a huge drop - something changed. It's essentially the same engine and chassis and aerodynamics. Drag coefficient has not changed. I suspect that the standard for measuring fuel performance must have changed.

I did check the Porsche web site and the numbers above posted by the OP are correct.

 

For the city mpg, I think the answer is obvious. Y'all are having a LOT more FUN driving it and launching your PDK's way too much! LOL

It has to be a different type of calculation given the highway mileage has dropped 20%! And that with an 8th gear (PDK) and 7th for MT.

What are some of you seeing re: mileage?

 

Pretty simple.

Porsche had to rely on the EPA doing the break in, coast down and certification in light of past non-conformance. Compounding that they now had to be robust for catalyst light off at Full Useful Life to the EPA’s satisfaction. The first causes measured fuel economy to be a bit pessimistic. The latter increases fuel consumption. Lastly under current rules the manual shift test schedule would have been the old Z schedule if Porsche did not have any data proving that customers shift differently than that. With the Z schedule fuel economy will get much worse with the more gears you have since it is based on set vehicle speeds for shifting out of each gear based on a four speed.

BTW my car just came back from a 1300+ mile trip where it averaged over 26 mph through mountains.

 

Agree with above, the EPA came down hard on the whole VW/Audi group.

My window sticker on my Manual Transmission 4S actually says 17/24 - so the base with PDK does 1mpg better in city driving evidently :-)

I have averaged over the 500 miles thus far (and most of it is backroad - non-highway) - 22mpg (I am doing break in so keeping it under 4-4.5K rpms much of the time). I am pretty sure on the highway, in 6th or 7th - you could get 26mpg. Which of my many cars, including family cars, this is my most economical car I have :-(

 

I am still driving

 

Not that I really care, but my mileage sucks. If you drive it properly, this will happen.

 

lol my daily driver is an F150 .. i'm loving this mileage

 

My 2019 GTS 7MT under lightly spirited driving gets 22 mpg. On track, about 12. When cruising long distance on the highway, I get about 26 mpg.

 

The Specs (graphics) that were supposed to show above but didn't were using 98 RON gas; URBAN fuel consumption was 14.5L/100km; Extra Urban was 7.3L / 100km and Combined was 10L / 100km.

OK, so please check my math and explain my "errors" in calculations. Above is taken from the EU 992 7MT specs, and 100km = 62.137 miles and 10L is about 2.64 gals. My calculations say those numbers above translate to 16.2 mpg (city/urban), 32.2 mpg (highway / extra-urban), and 23.5 mpg combined. Now, I understand that 98 RON gas is about 93.5 octane in the U.S. and I only use 93 but these calculations still baffle me. The best highway mileage I ever got in my 996TT was about 27.5 ... it was usually quite a bit lower given the speed I usually drive. I find it hard to believe those are published numbers.