The NEXO managed to reach a top speed of 106.16mph (171.98kph) while the Sonata topped out at 164.669mph (266.76kph) at the Bonneville Salt Flats on September 25, however, both records are subject to FIA homologation.
The two concepts were developed and tested by Hyundai America Technical Center, Hyundai Motor America and Hyundai Motor Company engineering teams ahead of its being put on display at the this year's 2019 SEMA show in Las Vegas, Nevada.
“I was thrilled with the privilege of piloting these two Hyundai land speed record attempts,” said Hyundai America Technical Center driver and senior powertrain engineer Dean Schlingmann.
Prior to the speed record for the hydrogen fuel cell category, the NEXO underwent some modifications.
Such modifications included an FIA-Approved Chromoly Safety Cage, SPA Technique Firesense by FireAde Suppression System, AutoPower Safety Window Nets, Simpson Racing Arm Restraint Nets as well as Sparco's ERGO Safety Seat and six-point safety harness.
Externally, the NEXO received a custom body wrap by Hyundai Design Center of Irvine and a high-speed under-bumper aero valence.
As for the Sonata Hybrid concept which attempted a land speed record for the petrol-electric hybrid category, it was fitted with KW Suspension's Competition level Strut/Shock/Spring package.
The wheels were swapped out for 15-inch Vision Rally 55 Race Wheels fitted with Mooneyes Moon Disc Wheel Covers and Goodyear Eagle's 28 x 4.5 Land Speed Tires that partially hid the custom high-speed Hyundai brakes By Hyundai America Technical Center Chassis Team
It also used Injen Technology's custom 3.0-inch exhaust system and was fitted with a Nitrous Express Maximizer EZ System, Programmable Nitrous Controller, Nitrous Express Dual Bottle Mount and “Wet” Fuel Rail Solenoid Package.
There was also an AEM CD-7 Digital Racing Display, C3 Fuels Supplied VP Racing MS 109 Race Fuel, custom four-cylinder exhaust header and custom software calibration package by Hyundai Motor Group in South Korea.
For safety, the Sonata received FIA Approved Chromoly Safety Cage, Sparco ERGO Safety Seat and six-point safety harness, SPA Technique Firesense by FireAde Suppression System, Simpson High-Speed Safety Parachute, AutoPower Safety Window Nets and Simpson Racing Arm Restraint Nets.
Externally, it sports a custom body wrap by Hyundai Design Center of Irvine and a high-speed under-bumper aero valence too.