zlacker

Other than a time lag (and petrol prices don't generally change often enough to matter IME), I can't say I ever noticed any of them being that inaccurate.

myAutomate (the owners of Petrolprices.com) talk about having "over 60 years combined expertise in the fuel industry", so I suppose I'd be surprised if it's all crowdsourced data - they've probably made arrangements with at least the big players, in which case the forced publication is much of a muchness?