No, tobacco [Manduca sexta] and tomato [M. quinquemaculata] aren't the same. But they're related. Both feed off tobacco and tomato plants. But the tobacco hornworm does prefer the tobacco plant, and the tomato hornworm the tomato plant.

Their larval stage is quite similar. But it's possible to distinguish between the two. For example, the tobacco hornworm has red horns and markings that are similar to seven [7] diagonal lines on its lime-green body.

In contrast, the tomato hornworm has black horns and markings that are similar to eight [8] v-shaped lines on its lime-green body.

The adult, moth stages for the two are similar. For example, they're both brown and gray. They both have spots on their abdomen. But the five-spotted hawkmoth, the adult of the tomato hornworm, has five spots. The adult, moth stage of the tobacco hornworm has six.