I am shopping for a pick-up truck to haul horses with. I thought I wanted a diesel because 1. the engines last longer 2. they get better gas mileage 3. they have more pulling power 4. I thought it would be more environmentally conscientious to use bio-diesel. Now I am having second thoughts as the price of diesel goes up and up and I just heard that things "grow" in biodiesel fuel in the summer and can clog your engine, etc. Need help deciding what to do! Want to be able to haul 2-3 horses, up steep hills (Colorado) and am buying used so need to keep it under $15K. Any advice greatly appreciated!!!