I was wondering, what is the differences between all the 5 series models? I dont know much about them Ive always drove 3 series...

thanks

The difference between the 5 series models is similar to the difference between the 3 series models. The model number normally designates the engine size. The larger the number the bigger the engine, and along with that the larger numbered models usually have more standard equipment that would be optional on the smaller numbered models. In 2008 there are 3 models, the 528i, 535i and 550i. The first two have the same engine as their 3 series counterparts. The 550i has a V8 engine.
Check out the BMW web site for more information.