budrichard

A big +1.
-Richard

Gonzalo38

I drive a 99.2 PDK Base Carrera and I've never been too worried about fuel consumption (I am in my Hybrid Cayenne...).

If I'm driving at speed limit in the highway, I can get 24 mpg but I'm usually around 20 or 21 because I tend to go just a little bit over the limit......

For short drives in the city, maybe around 12 mpg or less if I'm having fun getting out fast from the traffic lights.

zathras

I've always recorded my fillups and mileage, and calculated the actual mpg. It began as a curiosity to see how it compared with the mpg that the computer shows and I've just never stopped doing it in the 3 years I've owned my 2013 991 c2 cab.

I discovered that the computer displayed figures are worthless if you want accuracy. They have never lined up with what the actual mpg consumption is. The computer figures have always been higher than actual.

I dd my car on a 30 mile commute, mostly highway, and I tend to drive it a bit on the faster side.

I currently am getting in the 21-22 range. However 3 years ago my actual calculated was in the 24-25 range, so it's lost some efficiency over time.

flickroll

+1 Every Porsche I have owned (VW Touareg too) has read 2-3 mpg higher on the computer than when calculated at the pump. When I had a Macan I used the computer for comparative purposes between tanks, know the reading was high. But for comparing tank to tank what the computer said was good enough for that purpose.

Driven991

34 mi round trips for work. Mixed driving 25 mph up to 65 mph. Hand calculated at the pump during fill up...avg 21 mpg.

Valvefloat991

While the computer mpg numbers rarely match the mpg calculated from the miles driven and the gallons added at fill-up, the error is just as likely from the fill-up procedure, as from the computer.

If you really want accurate mpg information based on tank fill-ups, you need to top off your tank very carefully. One good procedure is to fill the tank until the pump clicks off. Then wait ten seconds and top it off again. Then wait ten seconds and do it again. It also helps if you always do this at the same pump at the same gas station.

Short of that procedure, your comparison of tank mileage versus the trip computer is little more than guesswork.

I'm much too lazy to follow this procedure myself. However, I have recorded my fuel economy since I bought my car last year and compare the tank fill-up with the trip computer mpg. Tank-to-tank, the computer has ranged from 1.5 mpg higher to 0.4 mpg lower. Over 7635 miles, the average trip computer reading has been 0.2 mpg higher than reality--or 0.8 percent.

Not bad at all. Perhaps the 991.2s have superior trip computers--among their other advantages.