In a large dutch oven, cook the beef and Italian sausage over medium heat until well browned. Transfer the meat to a large bowl and set aside.
Add cooking oil to the dutch oven and heat over medium heat. Add the onion, green bell peppers, red bell peppers, and garlic. Saute about 7 minutes or until the vegetables are tender.
Add the zucchini and saute another 3 to 5 minutes.
Add the meat back to the dutch oven.
Stir in the oregano, salt, black pepper and red pepper. and cook for 3 minutes.
Add the crushed tomatoes, diced tomatoes, tomato paste and sugar. Stir thoroughly and bring to a boil.
Reduce the heat and simmer for an hour or two.
Cook pasta according to the package directions. Drain the pasta.