I have a 2007 NBS with the 4.3 V6 and I was wondering if anybody else was getting bad fuel mileage out of it? I'm averaging around 13-15 miles per gallon which is far below the advertised 21 miles to the gallon.

 

I have a 99 with the 4.3 V6 with 165,000 miles and I still get around 17 mpg.

 

My 2000 Silverado used to get around 22 mpg, then after putting the fuel injector system in I was getting around 27, but now it's dropped severely to around 15. I freaked out naturally but it's only been about 2 years since I gave it a full and complete tune-up. It has 227,000 miles, still runs and pulls fantastic though.