Most of the low-hanging aerodynamic fruit has already been plucked from the engineering tree. Truck makers and their design teams are now actively exploring options they would have ignored a decade ago. It's all about the cost of fuel.

The big shift to slope-nosed aero trucks began nearly 20 years ago, and since then engineers and designers have been refining the design. Today we see tweaks and twists yielding just the tiniest of gains, yet they are all steps in the right direction. What follows is a pictorial review of some of the changes we've seen in recent years -- some dramatic, some very subtle, but all aimed at killing fewer bugs.

By Jim Park, Equipment Editor