Synthetic Bad for the TSX

[rh77]

A week or so ago, I changed the oil in the TSX from the Break-In oil to a fully synthetic variety. The owners' manual stated that the weight must be identical to that of the "dino-oil" variety, and so, in went 5W-30.

Since then, FE has decreased, and the car does not pull hills with the same efficiency as before (as noted by the FE meter on the dash and the cumulative avg. at the end of the tank). This has been separately confirmed by my wife,

"The car doesn't have the pep it did before the oil change".

She tries to hypermile using the feedback meter as well.

I spoke to another Honda owner today who had a similar experience in an 04 CR-V, and with the replacement of Dino-Oil, FE and power increased back to normal levels.

Now, what in the H-E Double Hockey Sticks is going on here??? Should the blend have gone down to 0W-30 -- then if so, the warranty may be voided for failure to follow the manufacturers specs.

Inquiry 1: Any idea why this would happen?
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Inquiry 2: When I changed the Break-In oil, there were all kinds of heavy-guage plastic shavings in the old oil -- is this normal for change #1?
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Inquiry 3: FE is down by at least 2-3 mpg -- how soon should I ditch this stuff and put regular oil back in? It was expensive but if it helps FE -- I'm crazy enough to do it.

THX

RH77