Best Ultra book for Mechanical Engineering College Student

Hi everyone, I'm new to this forum but I'm hoping I can get some of your opinions. I am not a computer tech expert, but I love great technology. I am familiar with a lot of the basics of computer parts and how they work, but I can't personally pick a great computer solely basing on my own knowledge.

Here is the list:

General Questions

1) What is your budget?

$2000
----- I'm actually only looking to spend $1500 max but I will most likely buy a used or refurbished laptop off bhphoto...

Best Ultra book for Mechanical Engineering College Student

Best Ultra book for Mechanical Engineering College Student