“My van is screaming its nuts off on the motorway”, is a common complaint & leads many owners of rear wheel drive Transits get in touch hoping a remap will fix it but it is a common misconception that a remap can change this.. Whilst more torque & a quieter tuned engine can sometimes give the impression of less rpm for any given speed travelled, its just an illusion,
The true solution is a different axle ratio, achieved by an axle or diff change.. if you have a 5.11 or a 5.13 ratio diff fitted currently, an indicated 70mph will be made using over 3000rpm.. Anything over 3000rpm can be noisy & uneconomical . I’d recommend around 1 “point” reduction so something in the low 4’s like a 4.27 would suffice without acceleration suffering too much. How about the 3.73 ? An excellent choice as 70 will come up about 2700rpm but a remap is needed to pull it if you’ve 100ps & on a 115 , it would pull that much better , so get in touch to discuss vantuner’ in house developed custom tuning options.
Vantuner doesn’t actually do axle / diff changes but recommends Transaxle Services in Halifax )