need help

[robo]

New to the diesel word, my dad purchase a 1996 Chevy C3500 duely 6.5 turbo. Changed oil, oil filter and fuel filter. Went on a trip pulling my 3000 lb trailer. Going up a hill we ended up at 28 miles per hour. The same trailer I can pull up the same hill with my 1988 Jimmy with stock 350 ending at 40 miles per hour. His diesel has189,000 miles on it purchased from original owner a friend of his. Is this normal???/

[phantom309]

New to the diesel word, my dad purchase a 1996 Chevy C3500 duely 6.5 turbo. Changed oil, oil filter and fuel filter. Went on a trip pulling my 3000 lb trailer. Going up a hill we ended up at 28 miles per hour. The same trailer I can pull up the same hill with my 1988 Jimmy with stock 350 ending at 40 miles per hour. His diesel has189,000 miles on it purchased from original owner a friend of his. Is this normal???/

No,...