I just bought my first Truck a few days ago, a 2003 Ford Ranger with 51,000 miles. It has a 3.0 V6. I filled the tank up the day I bought the truck, and I am averaging about 7 mpg. I live in Hollywood with alot of stop and go traffic but I figured it would get better mpg than a semi truck. I know something is wrong I just need some advice as to which direction to take.

 

When was the last time it was tuned up? Check air filter, plugs & wires, etc. Check engine light on?

 

My 2002 with a misfire 3.0L still manages 20mpg hwy.

Like stated before check plugs wires fuel filter o2 sensors. Any check engine light codes should be scanned to give you an idea on where to start.

 

I changed the air filter when I first bought it, it was slightly dirty. No check engine lights. No oversized tires or anything, It seems most likely it would be a sparkplug problem the more and more I read. I just didn't realize sparkplugs would create such a significant difference in mpg's

 

Wow, yes they do but also look at the wires and all of the boots to see if there is any signs of cracking and maybe even a carbon track to indicate a possible shorted wire.

What about the coil, is the spark strong, a blue color if not think on replacing it too, maybe n aftermarket unit with a little more output power to help get thing burning better in the cylinder.

Is your 4x locked in by any chance ?

ltr

 

Screamin Demon makes a pretty good upgraded coil.