Originally Posted by gta18

hi, i have been driving my truck for more than a year now and had my gas mileage in the highway at 15mpg and 12 in the city. Is there any way to improve this? or is it normal for this truck. i have been doing regular change oils and air filter change every 10k miles, but never checked my plugs. i bought the truck used with 75kmi on it. right now it has 96kmi.
help please
thanks
arnold