I have an '06 3.7L V6 with 62500mi. with K&N CAI and VX exhaust with dual side exit tips infront of right rear tire. Lately I have been getting great gas mileage, right now Im just under 1/2 tank with 250 miles. Normally its at around 200 miles. My driving style hasn't changed, if anything Ive been more aggressive over the last two weeks.

Question 1- When Im accelerating on the highway, at around 50-55 mph, the tach drops from 2500 down to 1200-1500. The engine sounds like I stepped off the gas. What is going on?

Question 2- Tonight I went for a drive and noticed that when I started up the truck it was idelling around 500, and continued to idel at 500 at stop lights. Was this just because my engine was warm, I had just gotten home about 1.5 hrs before?

 

Welcome to the site. What maintenance have you done to the truck? Replaced spark plugs? Ever cleaned the throttle body? Those two things might help if you havent done them before