I have owned jettas and passats in the past and all have given me good mpgs. I recently bought a 2006 2.5 jetta and it is giving me 18 mpg. Is this normal? I changed out the plugs, checked the intake (it is clear) and the filter looks clean. So what could be the problem. The old plugs look clean and there is a little bit of carbon buildup on the muffler. The estimated mpg is 22/city and 28 hwy and I am not even close.

Can anyone help? It does not hesitate or backfire and it only has 78K? any ideas? My neighbor suggested I have the injectors cleaned, but that doesn't make sense bc it is running rich (lots of fuel is being consumed, right?)