LexVan

In my experience, using Sport/Sport Plus mode 'costs' about 3 mpgs (+/- 1 mpg) in like/like conditions; highway cruising. This is mainly due to the cooler oil conditions (optimum mpgs are oil temps in the 228-232 range.....while in Sport Plus, oil is about 194-198). Also, when you defeat Auto Stop Start, you also defeat the 'sailing' mode when highway cruising. This will rob you of about 1 mpg too......even with a manual.....which is surprising.

So in review, for optimum 991.1 mpgs on highway cruising:

Normal mode-hot oil
PSE off
Auto Stop start activated for 'sailing'
Rear wing down- keep below 78 mph
7th gear
Cruise control
Good tire pressures

Dan Nagy

That's valuable information, thanks. The MT A/S/S and PSE info was a real surprise for me. I am going to give that a go for fun.

LexVan

I've been tempted to pull in my manual mirrors, but I'm not that crazy.

Valvefloat991

Is there a "sailing mode" with a manual? I don't think so.

arter

4.7 mpg on the track ( onboard readout doesnt go below 9....

LexVan

I didn't think so either, but it does do something in my 7MT.

koala

1 highway, 0 city.

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jungkim1234

This was on my road trip back from LA to Portland. I think this was the LA to Monterrey leg going up Highway 1 . '13 4S Cab, one passenger, fully loaded for a week road trip with various stops and some LA traffic. Driving normally with top down the majority of the time. I'd say pretty impressive considering all of the variables.

LexVan

Here's another tip:

91 octane with 0% ehtanol will add about 1-2 mpgs over 93 octane with 10% ethanol.

Wujohn

Do you have to slow down/speed up much? Traffic may be my primary issue here. Guess I will have to take a trip to Vegas to test out a less crowded drive...Any excuse I can use.

BTW, when I am in my wife's Prius I pass just about everything...it is, um...exhilarating.

gabbar

Just drove the 911 T in traffic and I see 11.8 MPG over 16 miles. 7MT / Sports mode

Scottish Pete

I left Temecula about 10:00 am heading south on I-15 to San Diego in my 991 C2S (not in Sport) and after 56 miles near Miramar following traffic at 80-85 showed 32 mpg.
For real mileage fun reset the trip meter to zero at the top of Tejon Pass heading north on I-5 to Bakersfield and with the auto start/stop engaged let it coast in "sail" from 65 mph up to over 90 mph for the next 5 miles or so of downgrade displaying 99.9 mpg!

Contadino

Picked up my 991.1 S cab in St. Louis and drove 600 miles home to Minneapolis. Got an indicated 31 mpg while my wife's Audi A4 following behind got 29.

LexVan

Congrats on your new Porsche. Some of my favorite Porsche roads in your great state are around Wabasha (I've done some volunteer work over the years at The Eagle Center) and the entire stretch of route 16 alone the Root River from Hokah, through Houston, Rushford, Lanesboro, and ending in Preston. Get 'er done!

LexVan

Not too much. I can easily average 72 mph on a +300 mile highway cruise on my regular trips to places like St. Louis, La Crosse, WI and Rochester, MN.