Motorists are being urged to fill their cars on Monday to avoid being stung at the bowser on Tuesday.
The average cost of unleaded petrol is set to increase by around 10 cents per litre to 128.0 cents tomorrow, according to FuelWatch.
On Tuesday most BP sites are increasing their unleaded price to 133.9 cents per litre, an increase of 15 cents.
Get in front of tomorrow's news for FREE
Journalism for the curious Australian across politics, business, culture and opinion.
READ NOWMost Caltex and Caltex Woolworths sites, meanwhile, are increasing their unleaded price to 130.9 cents per litre, while most Coles Express and Puma sites will rise to 129.9 cents per litre.
On average, the cheapest days to fill up in Perth are Sunday and Monday, with Tuesday and Wednesday being the most expensive.
However, there are still more than 30 sites selling below 117 cents per litre on Tuesday.
Monday’s cheapest unleaded is available for:
· 110.9 cpl at BP Maida Vale in the East;
· 109.5 cpl at 7-Eleven Haynes (Armadale) in the South; and
· 109.5 cpl at 7-Eleven Wangara in the North.
Tuesday’s cheapest unleaded will be available for:
· 113.7 cpl at United Roleystone in the East;
· 109.5 cpl at 7-Eleven Haynes (Armadale) in the South; and
· 109.5 cpl at Caltex StarShop Wangara in the North.