Perth motorists are being urged to do their research before filling up on Wednesday, as one retailer hikes prices by a staggering 23.6c while others provide relief.

The run of much needed petrol ease at the bowser will come to an end in Perth according to FuelWatch, as the average price of ULP is set to go up come Wednesday. Rising from Tuesday’s 189c a litre up to an average of 193.9c a litre.

Although eagle-eyed bargain hunters can snag a deal at the bowser if they plan ahead, with select retailers dropping prices on Wednesday despite a city wide hike.

Any motorist that decided to not fill up on Tuesday will be rewarded at United, with the chain’s prices dropping 4.7c to Perth’s cheapest average offer of 180.5c a litre.

Vibe will also offer Wednesday relief, while Caltex, BP, Ampol and EG Ampol are all set to spike up prices.

The cities biggest rise comes from Ampol, with the chain hiking the average for ULP up a whopping 23.6c for Perth’s most expensive on hump day at 209.7c a litre.

Reddy Express and 7-Eleven’s average prices will remain steady when the calendar turns over at 187.9c and 193.9c respectively.

Despite the uptick in ULP prices, diesel drivers will welcome a generous drop in price down to 270.1c a litre, an 8c difference.

Diesel’s dramatic trend continue’s, following a horror peak of 326,4c a litre on April 9, it will be down 56.3c in a 13 day span come Wednesday April 22.

All the major regional cities and towns across the state will see bowser relief despite the metro’s petrol pain, with Kalgoorlie/Boulder tipped to see the biggest drop of 5.5c a litre.

Where to find the cheapest fuel in Perth on Wednesday:

• Burk Landsdale and Liberty Landsdale in the north at 175.3¢ a litre
• Burk Cannington in the east at 173.3¢ a litre
• Burk Oakford in the south at 173.3¢ a litre