Just wonder if anyone has converted a manual fan and fan clutch to a electric only fan. My 99 Silverado xcab 5.3 usually get about 14.5 mpg in town but this summer we have had over two months of 100+ degrees heat here in Texas. I notice that the fan clutch is engaged mostly all the time now hence my fuel mileage has dropped to 12.5 mpg. I believe this is the cause. Of course the super hot air temperature doesnt help either. On the highway its the same about 19 mpg.