Make tab insert 4 spaces

Question

I want the tab key to insert four spaces. No matter what I do, it inserts 2 spaces. Here's the code I thought would work:

(setq tab-width 4)
(setq indent-tabs-mode nil)

I also have this set for a single mode:

(setq c-mode-hook
    (function (lambda ()
                (setq indent-tabs-mode nil)
                (setq c-indent-level 4))))

What am I doing wrong?

Answer 1

This question over on SO shows a few different ways to do it.