What percentage of the engine's power is transferred to the front vs. the rear wheels for the X3 and the X5? I'm looking at buying new.

Do they both have the same AWD system? Where can you suggest I look to get the most details about these BWM AWD systems?

Thanks, in advance. Nice to meet you here.

This is generally a good resource about most things X5:

http://www.x5world.net/

Don't know if you will be able to find an answer to your question there but worth a try.