Buyers of the 707 horsepower Dodge Challenger SRT Hellcat likely have little care for their fuel mileage, but it is far above the single-digit range the 426 Hemi was known for (and above some other supercars): owners can get 22 mpg on the highway, according to Chrysler/EPA testing, if they use the eight-speed automatic.

The Chevrolet Camaro ZL1, which has a supercharged 6.2 liter V8 is rated at a much lower 12 city, 18 highway with its automatic (16/19 with the manual). It is rated at 580 horsepower, and starts at $55,505.

The 2015 Challenger Hellcat, with a supercharged Hemi V8, lists at just under $60,000. It can run 10.8-second quarter miles (NHRA certified), making it the second fastest muscle car every measured, after the Charger Hellcat; Chevrolet rates the fastest ZL1 at 12.0 seconds (the automatic coupe). The 7-liter Z28 (505 hp) quarter mile time is close at 12.04 seconds; the Z28 costs $75,000.

Hellcat-Engine-Web

By comparison, Chrysler noted that the (Volkswagen) Lamborghini Aventador Roadster, at $425,845, generates 700 horsepower but goes just 18 miles on a gallon. The $287,820 Aston Marton Vanquish, with 576 horsepower, is also at 18 mpg, while the Mercedes SLS AMG GT, at $221,580, pushes out 583 horsepower and is rated at 19 mpg.

The Chrysler-developed Hellcat engine boasts a forged steel crankshaft with induction hardened bearing surfaces that can withstand 110-bar firing pressures.  The heads are heat-treated and optimized for thermal conductivity. The twin-screw 2,380-cc/rev supercharger has integral charge coolers and an electronic bypass to keep boost pressure to 11.6 psi or less. Air temperatures are kept below 140° F by twin air/coolant heat exchangers, integrated into the supercharger housing, which allow airflow of 30,000 liters/minute. The setup was designed to assure constant power through 20 laps of a 3.1 mile road course at an ambient temperature of 100°F.

Stryker Red Challenger Hellcat #1

The handle the torque, Hellcat cars with automatics have one additional pinion gear in each of the 1st and 3rd gear sets, and five more clutch-pack disks – two in clutch E and one each in clutches A, C and D.

With the six-speed manual transmission, economy drops to 21 mpg. This transmission has an internal cooling pump and external oil cooler, with a 258 mm clutch.

Dodge did not release city or combined mileage, and the EPA has not yet posted Hellcat figures on its Web site. The standard Dodge Challenger SRT8 (485 hp) achieves 15 city, 25 highway with the automatic and 14 city, 23 highway with the manual.

The Dodge Viper is rated at 12 mpg city, 21 highway.