Shell New Zealand announced a further 4 cent drop in the domestic retail price of petrol on Monday.
The retail price was also lowered by 4c on Thursday.
Shell dropped the price of 91 octane to $2.10.9 per litre on Monday. Diesel was unchanged.
Caltex has not dropped its price and says it has no plans to at this stage.
New York's main oil contract, light sweet crude for August delivery, closed at $US128.88 a barrel on Friday after falling by more than $US15 since Tuesday.
In London, Brent North Sea oil for September delivery was at $US130.19.