A new pocket-rocket is emerging in the U.S. market, driven by tougher federal fuel-economy standards and buyers wanting more bang for their buck.

All-new punched-up small cars coming soon include B-segment products such as the  Chevy Sonic RS, Fiat 500 Turbo and a widely expected but yet-unconfirmed Ford Fiesta ST.

Unlike the hot hatches of the last decade, the new breed is smaller, cheaper and more fuel-efficient. At the same time, it delivers on the promise of genuinely superior driving dynamics by eschewing an old industry practice of dressing up standard models with stickers and badges, but few mechanical upgrades.

Exterior styling is much bolder and interiors are filled with quality materials and the latest gadgets.

“There are buyers out there who find that this size of a car can work for them, but they don’t want a cheap car,” says John Buttermore, lead development engineer on the Chevy Sonic and Sonic RS.

“They want heated leather seats, they want a touchscreen, they want more than what your typical small car delivers,” says Buttermore, who brought his experience as a Corvette racing champion to engineering the Sonic lineup. “But you’ve also got to have a little bit of bite to go with the bark.”

Strict new federal fuel-economy rules, peaking at 35.5 mpg (6.6 L/100 km) in 2016 and 54.5 mpg (4.3 L/100 km) in 2025, also are driving the potent little cars to market. By easily achieving greater than 30 mpg (7.8 L/100 km), they feed the consumer’s need for speed and fuel economy, and allow auto makers to sell more highly profitable sports cars and trucks powered by less-efficient V-6 and V-8 engines.

“Because of federal fuel-economy regulations, we have to sell more of the sippers,” Dave Leon, GM’s chief engineer-performance cars, says during a recent industry event in Royal Oak, MI.

Consumers already are gravitating toward small cars in bigger numbers. Last month, the industry delivered 245,000 small cars in the U.S., for 20.7% of the light-vehicle market, according to WardsAuto data. That’s the second-best share performance for the group this year behind 20.8% of sales in March.

Ford continues to stop short of confirming a Fiesta ST for the U.S. market, but the auto maker has one under development for Europe and insiders say it’s almost certain to arrive in North America.

If the Fiesta indeed makes it stateside next year as expected, it would come on the heels of the slightly larger Focus ST to further broaden Ford’s performance offerings at the lower end of the market.

“One of the key things going forward is to offer a balanced performance portfolio,” says Jamal Hameedi, who as chief nameplate engineer for Ford’s SVT operations decides which of the auto maker’s cars will receive performance treatments.

“It is about offering a wide array of performance,” says Hameedi, who spoke alongside GM’s Leon at the Royal Oak event.

He admits the auto maker today exercises more restraint in adding performance editions to its products.

“We look at every platform, and if we think we can hit it out of the park, we’ll do that,” the Ford engineer says. “But we don’t want to make performance cars just because we can. We want a very good execution we know will beat the competition.”

Enthusiasts want the same things from an entry-level model as the folks buying more expensive muscle cars, such as Ford’s monster Mustang Shelby GT500, Hameedi contends.

“It is the exact same mindset,” he says. “So it becomes a matter of what is available. (The buyer) wants to go fast, so what do you have?”

The Fiesta ST under development for Europe uses a 1.6L turbocharged and direct-injected EcoBoost 4-cyl. engine, making 180 hp and 177 lb.-ft. (240 Nm) of torque, as unveiled in concept form at the Frankfurt auto show a year ago.

Hameedi says it also boasts plenty of other bells and whistles typically found further up the food chain.

“It’s a very fun car to drive,” he tells WardsAuto, saying Ford benchmarked the Volkswagen Polo in its development. “It’s lightweight, the steering is awesome and it is so nimble.”

The 5-door Sonic RS uses the nameplate’s optional 1.4L turbocharged Ecotec 4-cyl. engine, which makes an identical 138 hp and 148 lb.-ft. (200 Nm) of torque. But Buttermore says his team “crunched down” the gear ratios of the 6-speed manual to enhance responsiveness.

Sonic RS models with a 6-speed automatic transmission receive a higher final drive for extra punch at cruising speeds. For example, at 70 mph (113 km/h) the Sonic RS revs at 3,000 rpm, compared with 2,200 rpm on the base model.

The Sonic RS also receives a stiffer suspension with reworked shock absorber internals and a ride height 0.4 ins. (10 mm) lower than the base model to enhance handling and appearance.

The Sonic RS benefits a number of other appearance additions, most noteworthy being leather seating surfaces trimmed with suede meant to keep passengers snug during spirited driving. The seats are exclusive to the Sonic RS in its segment and price point of $20,000, GM says. It also receives Chevrolet’s new MyLink infotainment system as standard equipment.

The Sonic RS arrives in the fourth quarter as a ’13 model alongside the Fiat 500 Turbo, which Chrysler unveiled in August with a 1.4L turbocharged 4-cyl. engine making 135 hp and 150 lb.-ft. (203 Nm) of torque and using its Multi-Air valve technology. It will retail for $19,500.

Other fresh products to the segment include the slightly pricier 200-hp platform-sharing Toyota FR-S and Subaru BRZ sport coupes, as well as the 138-hp Hyundai Veloster sport coupe.

If the ’12 Veloster is any indication, the segment could see more entries in the coming model years.

Hyundai Motor America President John Krafcik recently boasted that the $18,000 Veloster stays on dealer lots only 13 days, making it difficult to sustain supplies even on sales volumes averaging a relatively modest 3,150 units per month. The auto maker recently added a pricier, more powerful turbo version for ’13.

Buttermore estimates the Sonic RS will grab somewhere between 6% and 10% of the nameplate’s annual sales, but adds coyly, “We’ll see how it goes.”

jamend@wardsauto.com