Sources say the Trump administration will on Monday unveil plans to relax restrictions on use of tax‑exempt red‑dyed diesel, potentially allowing broader use including on‑road vehicles. Red‑dyed diesel is exempt from the US federal 24¢/gal excise tax; any expansion of permitted uses would likely flow through quickly to lower retail diesel prices. Diesel has jumped after refining and shipping disruptions linked to Russia and Middle East conflicts; AAA data show US retail diesel averaged $6.32/gal as of Sunday, well above $3.76/gal in February. Higher diesel costs have pressured farmers, truckers and logistics sectors; the move appears aimed at cutting fuel costs ahead of November midterms.(金十)