I was also interested in this issue somehow, and I found a very useful blog with information about mobile homes
https://treehousetowns.com/. All foundation systems must comply with the guidelines published in the HUD Handbook. The most common types of foundations that are used in the construction of a mobile home are supports, slabs, basements. The most economical option is slabs on a flat foundation. On the blog you can find an article about the type of foundation and see a detailed description of each option.