Tune Up? When do we do it? (2010 4.0)

Mileage is taking a hit lately. Some info on my truck: 2010 TRD OR 4.0 MT 3" lift 285's on Stocks. My tires are Load range C so they arn't super heavy. My driving is mostly Hwy, 45 Mph+. My Milage was at an avg 17-19 MPG now its at best (3 tanks) 15.3 MPG. The truck has just over 35k miles and is mostly used on weekends.

 

You should do the spark plug change every 30k. These trucks have regular old copper spark plugs so you're definitely due. There's a great write up on here somewhere that shows step by step how to do it. Takes about an hour if your familiar with mechanical repairs.

 

Thats what I was thinking. I work @ NAPA so I was looking at the factory plugs and was disapointed when I saw the copper plugs.