help! my 97 f-150 4 x 4 extended cab 4.6 l. auto.got 7.74 MPG coming from Gresham, Or. to La Grande! That's 254 miles.With no real payload. You could watch the gauge go down...oww! Had a new air filter...has a topper...won't stay in cruise control on hills set at 75 mph...pretty gutless!!! Starts fine ,runs clean on spark plugs and all around the valley. Uses oil but doesn't burn it. Help please, Thanks in Advance !!!

 

Sounds like clogged cats to me.

 

I get 23-25 in my Vic on the freeway.

 

Agreed, but why? They don't just spontaneously melt down.

My SuperCrew got 17.5 MPG or so pulling the cousin's loaded 5x8 UHaul trailer to Orlando. Cruise set to 75, 3000 RPM jaunt up hills and down.

Time for some good ol' fashioned diagnostics. I'd be starting with compression check myself. I think I recall my old '94 Ranger starting fine, too. Even when it was running 0 PSI on #4. Granted, you'd think OBD2 would point something out...