When near enough is just not good enough

摘要

The single most effective piece of air-management kit on an articulated truck is a roof-mounted spoiler. That much about vehicle aerodynamics is so firmly established that nowadays any tractive unit without a roof-spoiler and cab side-deflectors looks odd unless it is hooked up to a tanker or car-transporter semi-trailer. But it is equally apparent that many a roof-spoiler is far from perfectly aligned with the height of the trailer behind it.rnPerhaps this should not be surprising, given the absence of any specific legal height limit for trucks in the UK and the resultant wide variety of trailer heights. Whatever the explanation though, big question marks are left hanging over the importance of precisely matching roof-spoiler and trailer height. In today's recessionary times with budgets under intense pressure, is near enough good enough?