Splitting sites similar to Diapers.com

[theoilhub]

Our site (theoilhub.com) sells automotive products.  We want to split it into multiple sites (autoparthub,com, motoparthub.com) and so on.  Some products will be listed on multiple domains because they have application in multiple domains (lubricants, helmets...).

I was wondering what the best solution was for avoiding any problems with Google detecting too much duplicate content from our sites? would doing rel=canonical help? Any suggestions would be appreciated.

[Serpstone]

rel="canonical" is not going to be of any help because you are dealing with separate sites. The only way to have the same content on different sites is to have that content made unique by rewriting it.

rel="canonical" would work with your current structure.

[MikeRoberts]

Cross-domain Rel="Canonical" does work but unique, relevant content where possible is always best.

[Serpstone]

Just because it works doesn't mean it should be used though. If you are saying "This content is more important on that site", then you could quickly end up with very imbalanced sites. If lots of content on a site has canonical tags to another site then surely it negates the purpose of having multiple sites to start with....

.... but the reasoning behind splitting up a site like that is another discussion entirely!