\documentclass{article}
\usepackage[latin1]{inputenc}
\usepackage[ngerman,english]{babel}
\usepackage{graphicx}
\begin{document}
ü%
\selectlanguage{ngerman}ü%
\fontencoding{T1}\selectfont ü%
\fontfamily{lmr}\selectfont ü

\selectlanguage{english}\fontfamily{cmr}\fontencoding{OT1}\selectfont
Ü%
\selectlanguage{ngerman}Ü%
\fontencoding{T1}\selectfont Ü%
\fontfamily{lmr}\selectfont Ü

\footnotesize
\rotatebox{90}{\strut CMR English}%
\rotatebox{90}{\strut CMR German}%
\rotatebox{90}{\strut ECRM}%
\rotatebox{90}{\strut LMR}%

\end{document}