That’s the warning from fleet management and funding provider Arval UK, which says the issue is likely to affect Luton and box bodied vans.
“Streamlining of custom bodies for light commercial vehicles has come a long way in recent years,” says Eddie Parker (pictured), LCV product manager at Arval UK, adding that aerodynamic features could boost vehicle fuel performance by as much as 5%.
However, the WLTP data being used for converted and bodied chassis only considers the frontal dimensions of the vehicle – any streamlining measures fitted by bodybuilders, such as aerodynamic collars and bulkheads, are not included, he points out.
While streamlined designs would still bring benefits in terms of the real-world mpg figures achieved by fleets, the overall picture would potentially become muddled, he adds, because there is “no widely recognised third party evidence of the positive effects of streamlining, which could have an effect on levels of adoption”.
Parker says that Arval UK is still supportive of WLTP in general: “WLTP provides buyers of vans, whether they operate one or a thousand, with a much better guide to how their vehicle will perform in the real world, which is something that we very much welcome.
“Also, the introduction of WLTP for LCVs has been much smoother than for cars thanks to lessons learnt by manufacturers at that time, especially when it comes to overall supply of vehicles. These are major positives.
“However, the lack of recognition for streamlining is potentially an issue and we believe there is a strong argument for revisiting the subject.”