No. Tigers are the strongest cat, not Lions.
Tigers are the largest and strongest member of the four big cats including Lions, Jaguars, Leopards(Panthers).
Measuring the strength compared to the size, Jaguar is the strongest cat according to pound for pound.
Tigers body construction is more same to Jaguar's body than Lions.
Tigers are more powerful than lion even they are in same size.
But Tigers are heavier than Lions and much heavier than Jaguars.
So it is clear that Tiger is the strongest cat.