A subsidiary of Mitsubishi Fuso Truck & Bus Corp. has systemically cheated on vehicle inspections by lightening the load capacity of 2,353 trucks over three years through 2004, transport ministry officials said Tuesday.

Of the 2,353 trucks, 1,230 were built for Mitsubishi Fuso and the remaining 1,123 for other truck makers, including Isuzu Motor Ltd. and Hino Motor Ltd.

Investigators from the Land, Infrastructure and Transport Ministry have discovered that the subsidiary, Pabco Co., based in Ebina, Kanagawa Prefecture, installed small fuel tanks in trucks to lower their total weight and replaced them with bigger tanks after obtaining inspection certificates, the officials said.