Wheel spacers

I read in LROI the other week about some tips on making ones landy more efficient. Amongst these tips was adding wheel spacers, I didn't have time to read the rest or buy the mag, but could someone ellaborate as to how or why it makes a series more efficient.
I'm thinking of making some since I have access to a lovely CNC miller that does what I tell it to.
So apart from the obvious gain in wider track, would I gain anything else?

Cheeeeeeeeeers guys.

Can't see why. Usual opinion is that spacers will put more load on the wheel bearings, so may lead to earlier failure.

Aye, fair point, anyone else got any views on said issue?

they claimed you could get a tighter turning circle, so would only use only, for example,a 3 rather than 5 point manuvre to get out of a bay- saving fuel.

don't know how much merit there is to it but i would be interested to find out as people seem to keep blocking me in at work.

end up costing more in wheel bearings though

You'd need to do an awful lot of tight parking to see that difference, and I suspect there will sly be a small margin when the slight difference in turning cucle will save you a shunt.