<h1>GST increase on hybrid diesel-electric heavy motor vehicles alters tax treatment for vehicles exceeding engine capacity or length thresholds.</h1> GST at forty percent applies to motor vehicles with both diesel (compression-ignition) engines and electric motors, where engine capacity exceeds 1500 cc or vehicle length exceeds 4000 mm; vehicle specification for classification is to be determined under the applicable motor vehicle specification rules, pursuant to Notification No. 09/2025 (IGST(Rate)).