Commonwealth Bank of Australia said that a limited conflict could lift crude oil prices by $5 to $10 per barrel on fear alone, but a wider war affecting Hormuz could push prices past $90 per barrel and lift US petrol well above $3 a gallon, according to a Monday report by the bank.

The bank noted that oil prices have surged more than 8% to their highest levels in months as the conflict has stepped up with renewed attacks, damaging tankers, and disrupting shipments from the key producing region.

The bank said, quoting Rystad Energy, that roughly 15 million barrels of crude oil per day, which is about 20% of the world's oil, is shipped through the Strait of Hormuz, making it the world's most critical oil chokepoint.

Tankers travelling through the strait, which is bordered in the north by Iran, carry oil and gas from Saudi Arabia, Kuwait, Iraq, Qatar, Bahrain, the UAE, and Iran, the bank added.

Scenarios before the current conflict foresaw a quick price spike that fades if the attacks didn't affect oil shipping and infrastructure, but it could lead to a bigger price spike and longer-lasting impact if oil infrastructure or supplies were interrupted because of the disruption of tanker traffic through the Strait of Hormuz, CommBank added.