pranavp

Hey guys, I'm posting regarding an issue I've had with my manual 2008 Porsche Cayman. I recently purchased this car after a prepurchase inspection which found no issues, in my driving nothing appears strange. However, over the course of driving it (my commute is mostly city driving, with a little highway driving) I have only been able to average 16-18 mpg, far below the 21 city/31 highway the car is rated for. I'm driving it in California, so it hasn't been getting particularly cold. What could be affecting the fuel economy? I haven't checked the tire pressure manually, but the tire pressure monitoring system tells me it is correct.

btwyx

I wasn't expecting good milage from this car, and that's exactly what we got. I have no idea how they got 21 mpg on the test, that's not how I drive. I'd be quite happy if I could get up to 16-18mpg around town, we're currently getting 13-15 (in a 2015).

The fuel economy cycle uses a driver with the aggression of a doped up granny, I can't drive that slowly.

extanker

perhaps a honda is a better choice of car for you. myself i aint havin fun until under 10 mpg

Spokayman

Have you checked your steady state mileage such as on an extended freeway run? You should see a pretty dramatic difference at 65-75 steady.
With an '06 CS, I've seen 18 at the worst and about 26 at the best. But, I've never commuted in heavy stop and go traffic.

Our Porsches are built to run pretty high RPMs compared to other vehicles in the 3+ liter class and that affects milage. Even my Hondas and Acuras cruise at lower RPMs than my Cayman.
The newer gen 987.2 and 981 seem to run lower revs though.

ottobon100

I have the same car - '08 2.7, 5-speed manual. I get about the same as you city driving. On a 440 mile freeway cruise I averaged 28mpg @ 65-75mph using Shell premium.