Rotella is designed specifically for Diesels, you can find it at any Walmart with an Auto Center. I would not put just any 15 W 40 in a diesel there are special additives in diesel oil that are not present in regular motor oil.
oil capacity in a 2000 ford f250 with a 7.3 lt diesel is 14 quarts
oil capacity in 2000 7.3 is 14 quarts
14 quarts
I was looking at the 2000 Ford F-250 , 7.3 Diesel Supplement and it shows : With engine oil filter change : ( 14.2 liters / 15.0 U.S. quarts )
According to the 2000 Ford F-250 , 7.3 liter diesel supplement : With engine oil filter change : ( 15.0 U.S. quarts )
Gas Engine: 5w30 Diesel Engine: 15w40
According to the 2000 Ford F-350 7.3L Diesel supplement : With engine oil filter change : ( 14.2 litres / 15.0 U.S. quarts )
15 quarts
According to the 2000 Ford E-350 , 7.3 liter diesel supplement : With engine oil filter change : ( 15.0 U.S. quarts ) * the Ford Motorcraft oil filter holds 2 quarts of the engine oil
15-40
According to the 2000 Ford Windstar Owner Guide ( 5W-30 )
gear oil