Most of the differences in building engines for off road SCORE or desert endurance racing purposes, say experts, concern the endurance factor. The annual Baja 1000 is actually 1,300 miles of punishing off-road racing. The winner will take 25 or 26 hours to complete the race, so the engines have to last for that long.
Double-dipping will make food go bad faster because it transfers saliva into the food, which promotes bacterial growth. One study even found that three to six double dips transferred about 10,000 bacteria from an eater's mouth to the dip sample. Putting leftovers away in a big clump may also promote food spoilage.
How long leftovers can safely stay in your refrigerator depends on the type of food and whether or not your fridge is truly keeping foods cold. It certainly saves you time and money to use leftover vegetables in a pasta or soup the next day, or leftover steak in a green salad. Err on the side of caution and safety, however, when dealing with leftovers in your fridge.