To turn off expandtab for editing Makefile

cut from vim wikia

http://vim.wikia.com/wiki/Converting_tabs_to_spaces

to get the following coding style,

• No tabs in the source file.
• All tab characters are 4 space characters.

use the following set of options:

:set tabstop=4

:set shiftwidth=4

:set expandtab

BUT

To turn off expandtab for editing makefiles, put the following in your vimrc:

autocmd FileType make setlocal noexpandtab