GCM & BTC Upgrades

Modifying a tow vehicle — through a GVM upgrade, a GCM upgrade, or heavier-duty suspension — can take it outside the specifications it was built and registered to. Without an engineer's certification, those modifications may not meet Australian Design Rules (ADRs), which can affect both roadworthiness and insurance outcomes. This guide explains what tow vehicle certification covers, when GVM, GCM, and ATM limits require an engineer's sign-off, and how the VSB14 and VSB6 codes

A factual guide to GCM re-rating in Australia, including how GCM differs from GVM and towing capacity, the engineering evidence involved, and why approval requirements vary between jurisdictions.

A factual guide to towing ratings in Australia, including GVM, GCM, BTC, ATM and GTM, how to identify the limiting rating and why approval pathways vary.