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Wheelbase change

Extending or shortening the wheelbase of a chassis.

Vehicle Characteristics
Within Less than 5% change in OEM's wheelbase and no changes to air system other than extending or shortening air-pipes and/or additional fitment of trailer connections or other components
Method of Inspection
  • Static inspection
  • Rolling road test
  • AUC’s only if not supplied by OEM with documentation

Vehicle Characteristics
More than 5% change of OEM's wheelbase, but within OEM’s envelope and no changes to air system other than extending or shortening air-pipes and/or additional fitment of trailer connections or other components
Method of Inspection
  • OEM’s envelope
  • Static inspection
  • Rolling road test
  • AUC graphs 1B
  • AUC graph 2 or 3 (only if towing unit)
  • AUC’s only if not supplied by OEM for full envelope with documentation

Vehicle Characteristics
Modifications outside OEM’s envelope and possible changes to air system other than extending or shortening air-pipes and/or additional fitment of trailer connections or other components
Method of Inspection
  • OEM’s envelope
  • Static inspection
  • Rolling road test
  • AUC graphs 1B
  • AUC graph 2 or 3 (only if towing unit)
  • Dynamic test type 0 unladen

Notes:
When extending or shortening the wheelbase of a freight carrier or truck tractor:
No dynamic testing required if:
New wheelbase dimension is within 5% or the range approved by the manufacturer. 
The converter has demonstrated compliance on different wheelbases of the same model through separate test reports. 
The system components must be the same as those fitted by the manufacturer (other than extending wiring and brake piping).
Dynamic testing required if:
New wheelbase dimension is outside the range approved by the manufacturer or if no manufacturer’s envelope is available. 
Dynamic tests of the type O in unladen condition should be considered only.



Please keep in mind that the regulator may at any time apply their own interpretation before issuing a NaTIS certificate.