Re: 2014 Jeep Grand Cherokee v6 Mods
I have an '11 limited and use a K&N air filter. Maybe a single mile per gallon difference but I have the 5 speed automatic. The 8 speed was supposed to bump mileage. A lot has to do with how heavy footed you are at stop signs and lights. MOPAR makes a cold air intake that is very similar in style to the K&N.
Good luck with the diesel. With all the environmental additions diesels just don't have the oomph they use to pack. Being a first year diesel has caused many headaches and buybacks. However is you live in a state that doesn't penalize you with massive diesel tax it might be a great move. The Rocky Mountain states and East Coast states have diesel fuel as much as a dollar higher than unleaded.