running rich/stumbling
 

So last night while doing some more of my break in driving I noticed my car stumbles around 1300 rpm when I put a load on the engine and clears up around 2000. I know these cars run rich but the back of my car is covered in carbon, I've been getting around 19-20 MPG and last night I tapped the throttle while idling and the car backfired. I'm only at 800 miles on the car and i'm about to take it to the dealer for this but just wanted to see if anyone else had something similar happen.

It really doesn't like running under 1,500 from what I've seen, hard acceleration is pretty much a no-no at engine speeds that low. It's happiest economically between 2k and 3k.

Also extremely surprised at the low mileage some people are getting, set cruise control last night for 80 and still getting about 30mpg... It really comes down to how you drive it, curious to see the outcome.