As DevilsRule stated, the Cruze is port fuel injected, although the rumor is it will get DI (GM refers to it as SIDI) in 2014 or 2015MY.
For whatever reason, be it injector nozzle design or not, GM seems to have more problems with Fuel dilution that some Fords such as the 2.0L DI engine in the Focus.
Their Ecotec 2.0 & 2.5l DI engines are having the same dilution issues, with resulting wear to critical parts such as bearings & timing chains as the 3.6 DI does.
Dexos sets a lower limit (13%) on Noack which helps a little with the intake valve deposit issue but does nothing to address the high pressure (up to 2250psi at high rpm) nozzles putting fuel past the rings into the oil, particularly when the engine cylinder temperatures are still low during cold starts and short, low speed trips.
Most of the SN GF-5 resource conserving oils just are not resistant to the thinning, commonly referred to here as shearing effects, of the fuel dilution.
It would seem that the latest VIs are geared more to temporarily shearing in the interest of maximum fuel economy, as opposed to non API oils such as Amsoil 5w-30 ASL or European ACEA oils.
These seemingly opposing oil specifications, resource conserving & robustness to the effects of fuel dilution in DI engines are being discussed in the GF-6 specifications being drafted.
Food for thought.
Gary