Changes in diesel fuel mean new challenges to the owners of diesel fuel-powered cars and trucks. 5 Star™ not only improves fuel economy and stability but also helps to keep your engine running clean and efficient. It will reduce exhaust emissions, clean injectors, increase cetane and corrosion protection, reduce power loss, and is an upper cylinder lubricant. In addition to these benefits, 5 Star™ contains cold flow improvers to enhance the fuel’s cold flow properties when it’s in sub-zero temperatures, making it the perfect choice for cold-weather dwellers. 32oz bottle.