Had my all stock 2006 roadster touring 6 speed manual several months now. Get a consistent 12 mpg with 91 octane from different major gas stations. Car runs and idles fine. Drive with top down and ac off. Tires are are michelin pilot sport and properly inflated and correct size. All driving is stop and go city. I drive moderately spirited. Mileage on car is 19,xxx so very low. Is this mpg typical under these conditions?

 

It all depends on your right foot

 

No.

 

Really? It's city driving though? I get 10-13mpg city and 21-23 highway. I haven't reset my gauge for the past 6,000 miles and I'm avging 20mpg from both.

 

Plenty of other threads on this topic already, but I'dd add that around town I get 15mpg in my '08 6MT. I don't think I'm too heavy on the throttle, and often shift 1-3-5. A few times I've tried to maximize miles on a single tank by short-shifting and really going light on the throttle, and funny thing was I ony got maybe 2mpg better, and it just wasn't worth the effort or loss of drivivng enjoyment.

To answer your specific question, 12mpg seems a bit extreme.

 

Given your mileage, you may still be on your first air filter. Try replacing it and see what happens.