The Roxx is not a stretched Thar. We explain what went into developing a ground-up new SUV that stays true to its origins
It’s the launch of the Thar Roxx in Kochi. The Mahindra team is presenting the SUV, turn by turn, subject by subject, to the public. Rajesh Jejurikar takes the stage, who makes a compelling case for the product positioning of the Thar Roxx. When the boss talks, everyone listens. When the boss talks, everyone listens. John Abraham is on stage to lighten the mood with Pratap Bose next, who explains the design inspirations behind the Roxx. Pratap then invites R Velusamy to the stage. Velusamy is an engineering tour de force at Mahindra and since the Roxx is driven by its engineering prowess, every journalist in the room is eager to know more. Gracefully, Velu says, “When Pratap designed this (Thar Roxx), we realised that we couldn’t rely on something existing. We needed to make disruptive innovations.” The spotlight is on Velu but he knows all too well that design and engineering are two sides of the same coin. The baton is now in Velu’s hands, soon to be passed on to the journalists, who are eagerly awaiting their chance to experience the Roxx. But first, they need to be equipped with the knowledge of the engineering effort that has gone into developing this vehicle.
It starts with an X-ray of the Thar Roxx, revealing its inner workings in full detail. Until now, the world has assumed it’s a stretched 3-door. But the Roxx is so much more. The engineering team holds over 60 patents for the Roxx. The frame is new, boasting both weight reduction and increased stiffness. The suspension is sophisticated, featuring a penta-link rear setup with Watt’s linkage. The engines over the front axle are uprated and Mahindra has introduced EPS for a more effortless driving experience. In about a minute, every scribe in the room is more curious than ever.
“The GLYDE platform that underpins the Roxx represents a total rethinking of how a ladder frame chassis is made”
John is just as intrigued, spelling out F = MA (Force equals mass times acceleration) in Velu’s masterclass. The GLYDE platform that underpins the Roxx represents a total rethinking of how a ladder frame chassis is made by Mahindra. Velu says, “We reduced the mass by 18 per cent.” While the frame’s mass is 18 per cent lighter, its bending frequency has increased by 41 per cent and the torsional frequency has gone up by a massive 51 per cent. Over 88 per cent of the frame in the Roxx is made of high-strength steel.
This reduction in mass has led to an automatic decrease in cornering forces, which we would experience firsthand once we were to drive the car. The Roxx is a revelation on the handling front, thanks to the stiffer and lighter chassis. The front suspension bears less load than it would if not for the innovative solutions by Velu’s team, allowing for a more pliant ride than ladder frame SUVs have any business delivering. But the suspension has also been upgraded with Frequency Dependent Damping (FDD), borrowed from the Scorpio-N. This means the Roxx not only promises a softer ride but also offers unparalleled stability for an SUV of this type. Even the rear suspension gets a Watt’s linkage, which prevents sway. Up-and-down movement is predictable; it’s the sway that can cause problems. But Watt’s linkage resolves that. It is arguably the most advanced suspension system designed in India, developed specifically for the Roxx’s purpose. The team at Mahindra engineered the Thar Roxx to handle long highway stretches just as capably as off-roading. On our highways, especially during monsoons when roads are cratered or over tall speed breakers, the Roxx is designed to take a serious beating without its occupants feeling the pain. Hydraulic Rebound Stoppers (HRS) are the final piece of the suspension puzzle, giving the Roxx its rough-road-crushing ability. Sirish would later demonstrate the real-world benefits of this on a 3000km road trip from Kerala to our home base in Pune on monsoon-ravaged roads.
“It is bolstered by a ring structure that functions like a roll cage. This reduces NVH levels in the cabin”
With ride and handling addressed, the question of NVH arises. A ladder frame SUV always faces a challenge in this area due to its inherent design. However, Mahindra has found an innovative solution, starting with a stiff body that sits on a rigid frame. It is bolstered by a ring structure that functions like a roll cage. This reduces NVH levels in the cabin, with the petrol Roxx recording just 39dBA at idle and the diesel showing 41dBA. These scores, similar to the monocoque XUV700, illustrate how much of an engineering step-up the Roxx represents, especially at lower engine speeds. The initial brief for the Roxx was to give a very car-like experience without losing out on the capabilities and on the NVH front, it more than delivers.
The presentation then moves to driving on tricky terrain because why wouldn’t one tackle challenging conditions in a vehicle bearing the Thar name? The Thar Roxx is equipped with a Brake Locking Differential (BLD) for the front axle and an Electronic Locking Differential (ELD) for the rear axle, sending power to the wheels that have grip. With its multiple programmed drive modes, the Roxx adapts perfectly to shifting terrain. Velu says, “The Thar Roxx loves sand, mud and snow.” When the low-ratio transfer case is in 4L, the Roxx also features IntelliTurn Assist (ITA), which brakes the inner wheel for a tighter turn, reducing the turning circle by 15 per cent — a simple yet effective innovation that is going to be very useful while off-roading. The Roxx is packed with innovations, far beyond what you’d expect in a car at this price point. CrawlSmart, for instance, is another off-roading feature that manages the engine, transmission and brakes when activated, functioning like cruise control for off-road situations.
Velu has spent 20 years working on Mahindra powertrains and the engines in the Roxx are evidence of how far they’ve come. Both the petrol and diesel units are now top performers in their segment. Electrically actuated turbochargers, flat torque curves and 0-60kmph times of 5 seconds for the mStallion and 4.8 seconds for the mHawk — these are quick and tractable motors. Paired with excellent 6-speed manual and automatic transmissions, the Roxx aims to deliver everyday drivability, competing with all the mid-size SUVs sold in India.
The engineering story of the Roxx concludes fittingly with a view of its metal roof and panoramic sunroof. From the days when Mahindra didn’t even make roofs for their CJs, to today’s metal-roofed Thar with a massive glasshouse, this image tells a thousand words, symbolising Mahindra’s journey to where it stands today.
Team Engage
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9 Dec 2024
