High gas prices are reviving an old pastime: obsessing over your car's gas mileage, Axios' Joann Muller reports.

• With gas averaging $4.28 nationally, drivers are rediscovering "hypermiling" — squeezing every possible mile out of a tank by laying off the gas and avoiding hard braking.

😨 Hypermiling was all the rage in 2008, the first time $4 gas had Americans staring anxiously at their fuel gauge.

• But the idea goes back much further: Drivers practiced similar fuel-saving tricks during World War II gas rationing and the 1970s oil shocks.

🛞 How it works: Hypermilers keep their tires properly inflated, accelerate gently, anticipate stoplights, coast whenever possible and religiously obey the speed limit.

• One Wisconsin man told The New York Times that he's getting 83.2 mpg from a Toyota Prius rated at 52 mpg. Gift link.
• There's another option: Engaging your car's "Eco" driving mode, if available.

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The contiguous U.S. just experienced both its hottest summer and hottest August on record, Alex Fitzpatrick writes from new NOAA data.

By the numbers: This past summer (June–August) clocked in at an average temperature of 74.4°F. That's 3°F above the 20th-century average.

• In August alone, the average temperature was 75.6°F — 3.5°F above the historical average.

🥵 Zoom in: "Record-breaking heat extended across much of the Southwest, with Arizona (tied), New Mexico, Utah and Colorado each recording their warmest summer on record," per NOAA.

• The records were driven in part by notably higher-than-average nighttime temperatures, with many areas experiencing little evening relief.

🌎 The big picture: Europe's Copernicus service says August was the hottest month on record for Earth as a whole amid human-caused climate change and a turbocharged El Niño, NPR reports.

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1. 🎤 In rare remarks about the 9/11 attacks, former President George W. Bush said at his presidential library in Dallas that many Americans "don't pay attention to the lessons of 9/11, because what happens overseas matters to our national security at home." Go deeper.
2. 📱 Apple is betting on "ambient AI" to bring new, useful and privacy-oriented features to the iPhone and Apple Watch. More from Ina Fried.
3. ✈️ Nashville International Airport's board is expected to vote in favor of renaming the field Dolly Parton International Airport. Go deeper.

Girl Scouts of the USA is rolling out its first cookies for dogs.

• The blueberry-muffin-flavored cookies, called Patch Pals, will be sold online starting in January.

🍪 Also coming this January: Sparkables, the group's first allergy-friendly cookie.

• The crunchy oatmeal cookie has chocolate chips and colored sprinkles.

Read the announcement.