okay so i have a 96 jeep cherokee 4wd 4.0l and for some reason over the last month or so it has been using a lot more fuel than normal.....any idea what could be the cause of this ?

 

So many things.

1. Vacuum leak (specifically throttle body to MAP) causing rich condition.
2. Faulty oxygen sensor causing rich condition
3. Cracked exhaust manifold
4. Fuel leak in soft lines at tank.
5. Dragging caliper or brake shoe.

I believe OBD codes are available for a '96, I would check those first.

 

Also, you get lower mpg with winter blend fuel. If you typically drive shorter trips, the engine doesn't get to warm up properly and causes the engine to run richer which uses more gas.

 

The E10 fuel only has about two thirds the energy of non ethanol blended fuels. It requires more fuel to do the same work as non ethanol gas. E15 is starting to rear its ugly head around the nation. DO NOT USE E15!!! It will destroy your fuel system.

 

Database of Non-Ethanol fuel locations:

http://www.pure-gas.org/