I had been getting bad gas mileage when driving the car hard with the jrsc. usually like 20mph in the city when I get on it a lot. I thought it was because I was running rich, seemed like it.

But when I went to check my plugs, I soon found that I was running lean.

I have since switched to my colder plugs and now run fine...in fact, I'm at 27-28mpg running around town like a maniac....this was my mpg stock in the city.

Here's a pic of the leaning out the plugs showed: