Motorists who see petrol stations driving up their prices over Easter should dob them in, the NRMA said today, as average petrol prices are predicted to be the lowest for this holiday period since 2005.

Prices in Sydney should be between $1.23 and $1.25 this weekend, an NRMA spokesman said, and should not exceed $1.30.

But if people notice petrol stations charging more than $1.30 in Sydney, they should use their mobile phones, or go online, to record the price on the NRMA's new motorist feedback website Road Tube, www.roadtube.com.au.

NRMA Motoring & Services President Wendy Machin said in a statement that people should not "suffer in silence" and should instead send video, photos or blog comments to the website.

Motorists can then log on and see which stations have the highest prices, and the data will be collected for the ACCC.