Replace the fuel filter and if that does not solve the problem you more than likely have a fuel pump going bad.
check your transmission mount for breaks or looseness
highway driving
If your 94 Silverado with a 96 Silverado transmission slips out of overdrive when you are on the highway, the gears may have seized up. You should also check the transmission fluid level.
The gas mileage of a 1981 Corvette can depend on whether it is automatic or manual transmission. With automatic transmission, it gets 15 mpg on the highway, and 21 in the city, but with manual transmission, it gets 14 mpg on the highway, and 22 in the city.
there is a part on the transmission called the torque convertor solenoid ..intown driving your car is not moving very fast,out of town or freeway driving your creating alot of heat ,the torque convertor solenoid is going out ,soon it will stall intown also as it gets worse.you can have it replaced or you can unplug it and your car will run fine ..the purpose of the solenoid is to downshift your automatic transmission when coming to a stop ..you can try this to be sure it is this part..shift car to neutral as you come to stop if car does not stall then that's your problem.if it does then it is most likely something in your throttle body ,idle control solenoid etc.,
19 city 27 highway with manual transmission 20 city 29 highway with A/T
According to www . fuel economy . gov ( no spaces ) For a 2002 Ford Explorer Sport with the 4.0 liter SOHC , V6 engine : Two wheel drive , automatic transmission ( 15 city / 20 highway ) Two wheel drive , 5 speed manual transmission ( 16 city / 20 highway ) Four wheel drive , automatic transmission ( 13 city / 18 highway ) Four wheel drive , 5 speed manual transmission ( 14 city / 18 highway )
In an ATX or automatic transmission expect 21 city 27 highway In an MTX or manual transmission expect 28 city 35 highway. This is all based on driver's experience, vehicle condition. My 2005 Neon will get well over 40mpg on the highway when driven correctly.
EGR valve
24 city / 32 highway / 5 speed manual transmission 23 city / 26 highway / 3 speed automatic transmission According to fuel economy . gov ( U.S. gallon )
The four speed automatic transmission is a 3 speed with overdrive for highway use.
the top gear, which will include overdrive. It will be the first selection after neutral.