There're few things more painful in life than filling up your car's tank, only to cruise by a station where it's cheaper, and realize what the price difference computes to in towering 2-for-1 Arizona Iced Teas. For a website easing your pain, check out MiamiGasPrices.
GasBuddy.com-powered MGP's a crowdsourced service selflessly devoted to finding you cheap gas in South Fla that also crunches the numbers on how to save you gas-cash on any US roadtrip, as well as alert you to the most expensive spots, where you can safely take a dump. You can find cheapo fuel a couple ways: there's a list of the 15 most-affordable stations (updated every 36 hours) with tabs to check regular, mid, premium, or diesel; you can also hunt via a "Bird's-Eye View" map broken down by color-coded zips indicating affordability, or zoomed-in showing icons for stations and their prices/contact info, so you can find the cheapest spot in the immediate 'hood, give them a ring, and brood on the fact that you just called a gas station. MGP also leverages GasBuddy's nationwide price tracking with spectacular results in their Trip Cost Calculator; give it your destination and car model & year, and it'll map out a plan to have you filling up at the cheapest spots (all within a 1/2-mile of your route) with the longest gaps possible between stops, plus tell you cash saved and even your carbon footprint -- which should shame you into just canceling the trip, but who knows if they'll have that pickled haggis festival next year?
Since it gets most of its prices from on-the-ground tipsters, you too can act as a price spotter; every tip you send in'll earn you points, and enter you into weekly giveaways where you can win $250 gas cards -- or, as you like to think of them, Tooth-Eroding Amounts of Mucho Mango Cards.