Regular tankers contain two flippers. Feel free to shoot them and their cargo with impunity. Fuseball tankers are very dangerous. Shoot them and get out of the way. Pulsar tankers are also very dangerous. Shoot them and stay where you are (the pulsars will appear to either side). You can differentiate between the types of tankers by looking closely at their centers. Fuseball and pulsar tankers have tiny pictures of their cargos in their centers. The ability to instantly differentiate between tanker types is probably the most important ability separating good Tempest players from great Tempest players.