The days of the naturally aspirated Fiat 500 are no more.

Fiat introduced the mildly revised 2018 Fiat 500 at the 2018 Chicago Auto Show. While there are changes to equipment on various trims, the biggest story from this debut is what's under the hood.

Instead of the old 101-horsepower 1.4-liter I4, all non-Abarth models now receive a turbocharged 1.4-liter I4. Output is up -- way up, to 135 hp and 150 pound-feet of torque. Front-wheel drive is the only layout on offer, but buyers can choose between a five-speed manual and a six-speed automatic.

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The two base trims -- Pop and Lounge -- also get some new standard equipment. 16-inch aluminum wheels, performance brakes, a sport suspension and a backup camera are all now standard. You also get a neat new "Turbo" badge and a sporty little spoiler. Fun! The fabric convertible top is back as an option, too, if you want some additional sun.

If that's not enough hustle for you, the 500 Abarth is back for another round of hot-hatch action. Its 1.4-liter engine is tuned to produce 160 horsepower and 183 pound-feet of torque mated to the same two transmission choices.

Abarth buyers also get additional kit, like a sportier suspension, three-mode stability control, black wheels and red brake calipers. There's also a dual-exhaust system that, as always, sounds way angrier than the car actually is. Inside, buyers get sport seats with bolsters and a pass-through for racing harnesses, aluminum pedal covers and a turbo boost gauge.

As before, Abarth buyers and lessees also get a one-day high performance driving class at the Bob Bondurant School of High Performance Driving.

The 2018 Fiat 500 goes on sale in the second quarter of 2018, and pricing has yet to be announced.