Pontiac – Mustang is the king of muscle-car sales.

Credit a striking new design, affordable sticker price and relentless introduction of thoroughbreds like the 526-horsepower 2019 GT350 that I just flogged around M1 Concourse's Champion Speedway. It sounds like a T. rex gargling razor blades and looks like your dreams.

But Mustang isn’t stopping there. The iconic pony has transcended its retro roots to become a brand ambassador to 146 countries — and a new generation of electric-vehicle buyers.

“(Sports cars) is a really important segment for us, we’ve been in it for 55 years. But globally last year we sold 113,000 Mustangs. This is one of our strongest brands and it’s important that it’s around for the next 55 years,” says Amy Marentic, who holds the newly created title of regional product line manager for Ford's Mustang, Bronco, Raptor and GT.

Her responsibilities signal the importance of touchstone models as the automaker transforms into an EV and SUV maker (to complement its F-series truck franchise).

After eating rival Chevy Camaro’s exhaust from 2009 to 2014, the sixth-generation Mustang has been a runaway sales hit. U.S. sales last year crested 75,000 units, the fourth year in a row it has taken the crown from Chevy and Dodge.

Relentlessly spitting out new model trims, the Mustang lineup is the most diverse ever with a 2.3-liter turbo-4, EcoBoost high-performance turbo-4, V-8 powered GT, V-8-powered Bullitt (after the Steve McQueen movie), convertibles galore, the snarling GT350 and — new for 2020 — the first-700-horse Mustang GT500.

“This is the most customizable year of Mustang ever, between the engine choices, aero choices and models like the Bullitt and GT350," says Marentic.

Despite competing against a Camaro that has outperformed the Ford in almost every technical comparison, Mustang has won over the segment on passion. That passion is tricky to bottle. Ford was questioned in 2015 about its revolutionary redesign of an icon that had fed on baby boomer nostalgia. But the modern 21st-century design captured a new generation of buyers.

While Camaro priced its more-athletic V-8 powered chassis $4,000 north of Mustang’s GT, customers were left cold by its design and cramped interior. Despite trailing the ferocious,650-horse Camaro ZL1 on track, Mustang stamped its GT350 with the legendary Shelby Cobra badge and turned knees to butter.

“We are proving new vehicles that bring new technologies and the halo strategy of the GT350 and GT500 that bring customers into showrooms,” Marentic at M1 above the din of a passing GT350.

This relentless focus on a mere 200,000 sales segment signals what Mustang means to the company.

When 'Stang barrels down the back straight of M1 Concourse at 110 mph, its V-8 is more than a thunderclap — it’s the signature sound of a high-tech flat-plane crank, 5.2-liter engine usually found in exotics like the Ferrari California.

More than a straight-line dragster, the GT350 is remarkably nimble around M1’s twisty 1.5-mile thanks to super sticky Michelin Cup 2 tires and rear wing shared with the GT500.

Ford hopes that passion for performance will translate to a new era of Tesla-fighting electric cars.

Coming next year, a four-door crossover electric vehicle bears the unmistakable Mustang three-bar taillights. Rumors that the car will be named the Mach 1 — after a '60s-trim Mustang — have quieted. But Ford is determined to translate muscle car macho to EVs as part of an $11 billion investment in 16 battery-powered models worldwide by 2022 — as demanded by government mandates and Chairman Bill Ford Jr.’s determination that Ford be a green pioneer.

Mustang pioneered the two-door pony car in 1965. The 2019 GT350 is light years beyond its forefather, the 1965 GT350. With electronically controlled anti-lock brakes and engine systems, the new car inspires hard driving around the M1 track that would turn your hair white in the ’65 car.

But the result is the same. The ’65 GT350 dominated 1960s Trans Am racing. Its namesake is a key reason Mustang is the most coveted muscle car today.

Henry Payne is auto critic for The Detroit News. Find him at hpayne@detroitnews.com or Twitter @HenryEPayne. Catch “Car Radio with Henry Payne” from noon-2 p.m. Saturdays on 910 AM Superstation.