Depends on weight (resistance to rotation) size (height-also resists rotation), compound (friction in softer tires) and width (contact patch-rolling resistance).

 

I'm back to 11Mph in the city......sigh You would think Im driving around in a gigantic V8.

 

Strat10, There is still something definitely wrong there is no way your getting 11mpg city. Are you freaking kidding me! I would check for leaks in tire pressure or your PCM gauge is off. Measure the mpg yourself for accuracy. Make sure your not carrying too much in your. trunk just the basics spare tire, jack, lug tool etc. Either this or you do for some maintenceA twin turbo 996 doesn't even reach 11 mpg unless your on it all the time.

 

Just did the 60,000 maintenance, so its not that. Tire pressure is good. I'm guessing its the stop and go driving I do going to work. on the freeway I get 20.

 

11mpg is on the lower side but can be expected with aggressive driving in the city. I avg 13-15mpg city partly due to my aggressive driving as well. When I drive on longer trips on the highway, I can get close to 28mpg so I know nothing is wrong with my car.

Top Gear had an episode where they were measuring fuel economy of super cars driven aggressively. If you haven't seen it yet, I would recommend watching it as it is very amusing and yet enlightening.

 

I have seen that episode, and agree with you on the spirited driving. It just gets confusing when people are claiming 19-21 in the city. That just seems like a huge difference. I guess it could be that our opinion of "spirited" is way off.

 

Our "spirited" might be more inline with the Stig's version.

BTW, here it is for others to feel better about.

http://www.youtube.com/watch?v=rgoDsiE5iMM

 

Could be because Strat you have a convertible maybe that makes a difference.

 

That makes sense, convertible much heavier?

 

I pulled this from MSN Autos This is for MY2000 911
http://autos.msn.com/research/vip/sp...1&trimid=92448

City (mpg) 16 - 17 Highway (mpg) 25

Curb Weight - Automatic (lb.) 3174 Curb Weight - Manual (lb.) 3075



So in conclusion your cars weight is really not that bad compared to a coupe.

 

Back to the Tapeworm theory

 

I have a Mk2 C4 Cab. I drive in Boston in stop and go traffic.
I keep tires at 36/44 and they're new Michelin Pilot Sports
And I have a new crate motor with all new accessories (AOS, alternator etc) from Porsche.

I can't get above 12mpg.
I've just learned to live with it.