How does insufficient tire inflation pressure (under-inflation by 2.0 bar) on a 40-tonne commercial vehicle combination affect rolling resistance and fuel economy?

1. It causes excessive tire flexing (Walkarbeit), increases rolling resistance by up to 15%–20%, elevates fuel consumption by 3%–5%, and risks catastrophic tire blowout from thermal overheating
2. It reduces fuel consumption because the tire contact patch is wider
3. It has no measurable effect on commercial vehicle fuel consumption
4. It reduces tire operating temperature on long highway trips