http://www.dieselwars.com/story.html What do you think about it? Should I write a longer and more detailed one (I made it short so people would read it)? What do you think about it? (I am much better with words in my own language, but I will need to write stories also in English for my games)

I like it. Not too long and not too short. Nice one.

Seriously, this actually looks like it could be a pretty cool game.
How far along are you in development?
As for the story, there are a few spelling errors here and there, but it's interesting. Personally, I like short back stories for games, but that's just a personal preference.

If you want to see where the spelling errors are, you can just paste it into this site: http://orangoo.com/spell/