Mayor de Blasio could follow his own advice by giving up his gas-guzzling 12-mile rides to a Brooklyn gym and switching his workouts to a fitness facility practically next door to Gracie Mansion.

Asphalt Green — just three blocks from the official mayoral residence — has plenty of the stationary bikes de Blasio uses for his four-times-per-week workouts.

It also boasts other “top-notch cardio and strength-training equipment” in fitness rooms with East River views.

A “passport”-level membership would set the mayor back a $199 initiation fee and $159 per month.

“This place is huge. It has everything you need in a gym and for the price, it’s not that bad for NYC,” said Erika Thompson, 24, of the Upper East Side.

“I’m sure he can get everything here without the cost of traveling to his preferred gym,” said Asphalt Green member Steven Russo, 28.

De Blasio was silent Saturday about the belief he expressed to WNYC host Brian Lehrer that New Yorkers “need to change our habits to start protecting the earth.”

During his interview with Lehrer, de Blasio refused to give up traveling to the Park Slope YMCA in an SUV motorcade. On Saturday, the mayor’s Chevy Tahoe hybrid was spotted in a “no standing” zone outside the Park Slope Y.

De Blasio’s flack, Eric Phillips, took to Twitter to denounce coverage of de Blasio’s hypocrisy in Saturday’s newspapers.

“Want to be mayor of New York City? Prep for the weighty municipal issues,” Phillips tweeted sarcastically.

A snarky Twitter user replied that de Blasio “deserves some credit. He may be driven everywhere, but at least he publicly claims to want to bike and take transit more.”

Phillips responded: “You’re missing the point from outer space. The mayor’s not a cyclist. It’s not his thing. The world isn’t ending.”

If he doesn’t want to switch gyms, critics say de Blasio would show real leadership by giving up SUVs for his regular trips to Brooklyn and using the subway instead.

“I don’t want to be the mayor’s scold,” said Charles Komanoff, whose call to de Blasio during the mayor’s weekly appearance on WNYC triggered the kerfuffle. “But there’s a transit crisis.”

Delay-plagued subway and bus riders “need a voice and we don’t have one,” he said. “It’s harder for the mayor to become the voice when he doesn’t use the system.”

Additional reporting by Eileen AJ Conelly