August RBOB broke out to a new four-day high during the initial morning hours, helped by follow-through action from yesterday's gain. Some traders were also pointed to the widening spread differential between July and August RBOB as a force reflecting a tight supply/demand situation. In the meantime, the latest data from the US Department of Energy showed US retail gasoline prices falling nearly $0.10 last week to an average of $3.437 per gallon. Early expectations for this week's EIA inventory data are for a build in gasoline stocks last week in the range of 750,000 to 1.0 million barrels.