Sentence 1: 5 mpg before the start of that model year

Sentence 2: In a previous model year they had achieved 4 mpg, but this model year they achieved 5 mpg.
Is this second sentence entailed by the first?

Answer: it is not possible to tell

Sentence 1: Napoleon's penis--lopped off during his autopsy--was purchased a few years ago by a New York urologist.

Sentence 2: Napoleon's penis was found missing during his autopsy.
Is this second sentence entailed by the first?

Answer: no

Sentence 1: Leather belts, bags, and shoes are very popular buys.

Sentence 2: It's popular to buy leather belts, bags, and shoes for loved ones back home.
Is this second sentence entailed by the first?

Answer:
it is not possible to tell