Ron's Octoberfest German Potato Salad

Bring a large pot of salted water to a boil. Add peeled and cut potatoes; cook until tender but still firm, about 15 minutes. Drain, and transfer to a large bowl. Add onions.

In a large bowl, whisk together the mayonnaise, oil, vinegar, sugar, parsley, salt and pepper. Gently stir in the potatoes and onion. Let stand for 1 hour before serving to enhance flavors.