I have a '90 Sambar Dias van, EN07Y supercharged, 5 speed manual that's been getting about 25 MPG, mostly in a 2 mile descent of 400ft in the morning, and a 2 mille 400 ft climb in the evening. It always gets close to 25 mpg. highway or city driving. Originally it was equipped with ac which has been removed. The 12 inch rims were replaced with 13's, yet the odometer converts to match the mile markers and the radar signs say I'm doing 31 at 50 km/h. The air filter seems to get a lot of oil blowback from the valve cover vent. I don't see a big difference when I change the filter. Recently I noticed that the engine room fan doesn't seem to be running. It appears to be designed to push air into the air filter, so I would imagine that it should be running all the time. All the fuses are fine. Does any of this sound wrong to any one one out there, or am I expecting too much gas mileage for running a supercharged 660 cc engine up and down a hill cold every day? The emissions smell pretty fueley.