I have noticed alot of black smoke when I accelerate fast. The fuel mileage has dropped from about 17 mpg to 15 mpg. I have right at 50k on her now and haven't really done anything lately but have both rear u-joints replaced and the differential fluids changed. Why the smoke now and how do I get more mpg's? I'm not a hot rodder and don't leave rubber when I leave a stop sign (I've grown up).

 

check your air filter first it may need to be cleaned.