[aerohead]

The year the S-10 went out of production,the"Extreme" model had all the candy on it ,and shooting from the hip ,had a drag coefficient of around Cd 0.40.The first gen S-10/ GMC S-15,with Cd 0.475,when modified with the California dress-up package,stretched -cab,drop-spindles,and half-tonneau achieved Cd 0.31 ( same as a Corvette of the day ) and a land speed record.On the road,that would have been good for a 17.5-percent improvement in mpg at 55-mph.More at higher speed.Wind-tunnel studies and results from mods some of the members have done, demonstrate that the single greatest gain for a pickup comes from the "aero-shell" style bed-cover,which can provide a 20-percent drag reduction and 10-percent-plus mileage gain by itself.You can see bondo's and mine here at the aero forum,there are more at the maxmpg website.Whatever direction you go,get some good baseline data,so you have a very good feel for what the S-10 is doing now.A number of members are using Scan-Gauge technology to obtain instantaneous readouts after mods,otherwise it's long hauls between top-offs before you know if your mods made any difference (and a lot of used-up fuel ).Temperature and weather will significantly effect your results ( that's why the big boys use wind-tunnels ).You could see 3-mpg improvement over winter driving with no mods at all.Best to you on the project.