Diesel forklifts run on diesel fuel. They can be refueled quickly and easily, but they require storage for the fuel, and the fuel can become expensive. These trucks have an internal fuel tank in the same way as a car, and can be refilled quickly and easily. Diesel forklifts are less expensive to purchase initially, however the cost of fuel quickly adds up, making them most expensive per use when compared to an electric forklift. Diesel powered forklifts must be used outdoors, as the emissions they produce are dangerous if inhaled in an enclosed area. These forklifts are made for outdoor use and many can handle rugged or rough terrain. Diesel forklifts can handle the largest loads, some up to 15,000 kilos, and can be also be used for pushing or towing.