General experience says crank whip = broken cranks, oil film failure = spun bearings.
There has been much discussion here on the DMD. If crank whip is the primary cause of engine failure, I would expect to see much higher failure occurance in the engines that had underdrive/solid pullies installed. Have we seen this?
I know this seems to go against the prevailing religion in this group but I would not expect to keep a 7000 RPM street motor together and healthy for the long run by using a 5-30 oil, synthetic or conventional. I have been a strong proponent of using Mobil 1 0-40 oil in todays high performance engines (just as Porche, BMW & MB currently do). Before you guys tell me how ??thick? it is, take a look at a few sources of information.
http://www.epa.gov/otaq/cert/dearmfr/ccd0112.pdf
The above is an interesting government publication showing the ??guidance? the feds give the auto and oil industries which mandates 5-20 wt. Oil. The same ??guidance? was issued some years ago concerning 5-30. This is not a suggestion from an automotive engineer concerned with engine life, it is a directive from a Federal agency concerned with forcing us to get one tenth of one MPG better fuel consumption at the expense of engine life.
Spend some time on the Euro and Australian web sites of the auto and oil companies and see what you find when they can talk without worring about EPA guidlines.
The Euro Castrol site has an oil selector page. It specifies 10-40 or 15-40 for the Mondeo.
There are several instances of referring to 10-40 as a ??lighter weight? viscosity here.
Mobil Australia has the same type of oil selector guide on their site. Even though there is a footnote indicating Ford reccommends 5-30, Mobil then specifies 0-40 as the oil to use in the Mondeo.
You all might consider an upgrade from 5-30 oil if you participate in ??spirited? motoring with your Contours and don't want the engines to go boom.