Change default width of images in graphicx package

Question

Is it possible to change the default width of an image included via \includegraphics (from the graphicx package) to a custom value, for example \linewidth.

So I want something like this:

\documentclass{article}

\usepackage[draft,width=\linewidth]{graphicx}

%or something like \setglobalimagewidth=\linewidth

\begin{document}

\includegraphics{test1} %width=\linewidth
\includegraphics[width=4cm]{test1} %width=4cm


\end{document}

Answer 1

Some options of package graphicx can be set using \setkeys:

\documentclass{article}
\usepackage{graphicx}
\setkeys{Gin}{width=\linewidth}

\begin{document}
  \noindent
  \includegraphics{test1}
\end{document}

Answer 2

I do not think that I have the perfect solution but I am happy with:

% Define new length
\newlength{\myFigureStandardWidth}
% Set the new length to a specific value
\setlength{\myFigureStandardWidth}{0.90\textwidth}

When I insert a figure then I just use something like

\begin{figure}
\centering
    \includegraphics[width=\myFigureStandardWidth]%
    {FigureName.png}%
\caption[Short Caption]{Long Caption}
\label{fig:FigureName}
\end{figure}

I am writing my phd thesis this way and have inserted over 50 figures this way.