One of the best checks you can do on your car, before a long trip, is to check the oil. Based on your vehicle's make and model, it needs between 3-5 quarts. When looking at the dipstick, keep in mind that you may need to restart your engine a few times to get all the oil OUT of the stick and also you can get more info for look up VIN number there. To avoid this, you could use a funnel or siphon tube to direct the oil towards an end point. In addition, make sure that none of it drips back into the dipstick area.