Found this on the Honest John website.
Modern petrol engines are built extremely 'tight' so they need a bit of wear during the first 10,000 miles for the piston rings to bed properly into the bores. Leave factory fill of oil for the first year or 10,000 miles. An early oil change to fully synthetic can prevent this happening, as can driving at low engine revs and driving at steady speeds. So, depending on the engine, self-impose yourself yourself a rev limit of between 4,000 and 5,000 for the first 1,000 miles, and be sure you vary your revs and occasionally reach that limit. After 1,000 miles, common sense dictates that you won't rev the nuts off the thing straight away, but you needn't be too worried about hitting 6,000 rpm occasionally as long as you vary the engine speed. Try never to rev to the rev limiter as the misfire this causes can damage the catalytic converter matrix. Don't change the oil and filter until the first manufacturer recommended change point, or the end of the first year. After that, if you intend keeping the car for a long time I still recommend more frequent oil and filter changes than the manufacturers or their on-board service indicators suggest. It's also a good idea to have the transmission oil changed after the first year to get rid of any swarf which could later be ground up into tiny particles which eventually get into the bearings and accelerate wear.