  Let $\ell$ be an odd prime, and suppose $E$ is an elliptic curve defined over
the rational numbers $\mathbb{Q}$. If $E$ has an $\ell$-torsion point, then
there has been significant work done on characterizing the $\ell$-divisibility
of the global Tamagawa number of $E$. In this paper, we consider elliptic
curves that are $\ell$-isogenous to elliptic curves with an $\ell$-torsion
point and study the $\ell$-divisibility of their global Tamagawa numbers.
