Isuzu Other Engine Poor Mileage

I Have A Kb 240 Le Petrol Engine. When Changing Gears And When I Come To A Stop Sometimes The Rev Meter Remains High Though My Foot Is Not...

My Isuzu Is Very Heavy On Fuel, 7.5km/l. What Can The Problem Be And What Can I Do About It?

I Have A 2000 Isuzu Rodeo Ls, 2wd, Automatic Transmission, 3.2l 6 Cylinder With 129000 Miles. My Gas Mileage Per Tank Has Dropped From 320...