Sure a tonneau is going to lead to an improvement, most noticeably in highway. I'll have to second on elhigh's advice on an electric fan, since it's a fairly simple mod and leads to some good improvements not just in fuel-savings but also making it easier to reach the operating temperature in a shorter time after the start, leading to smoothier idling and also increasing the efficiency of the catalytic converter since the "cold phase" becomes shorter.
|