Launched in early 2023, Project Cavendish is a £9.8m (US$13.2m) program supported by the Advanced Propulsion Centre UK (APC) to develop end-to-end hydrogen powertrain capability for heavy-duty applications and enable the UK’s transition to net zero transportation. As part of the project, Mahle Powertrain has upgraded its testing infrastructure in Northampton for hydrogen operation.

“This milestone demonstrates that hydrogen combustion has a place as a clean fuel in the heavy-duty market,” said Jonathan Hall, head of research and advanced engineering at Mahle Powertrain. “Achieving the target torque and low raw engine-out emissions from a hydrogen-fueled 13-liter heavy-duty engine represents a significant step forward, both for Mahle Powertrain and for the wider industry, as we move toward practical hydrogen combustion solutions for heavy-duty applications.”

Achieving target torque is just the first step, says Mahle; the bigger challenge in hydrogen combustion is controlling NOX emissions. The measured raw engine-out emissions of its converted engine are very low and the addition of a simple selective catalytic reduction (SCR) aftertreatment system will enable the tailpipe emissions to be significantly less than EU VII limits. The measured particulate emissions were negligible and readily manageable using existing particulate filter technology. The results demonstrate that hydrogen combustion engines offer a practical, fast-to-market pathway toward zero-carbon heavy-duty transportation.

Project Cavendish also aims to facilitate wider hydrogen adoption by creating opportunities for external partners to undertake hydrogen engine testing at Mahle Powertrain’s facility in Northampton. The site serves as a center of excellence for the design, development, calibration and testing of all aspects of hydrogen and renewable-fuel powertrain engineering. Mahle Powertrain has reported growing interest from new customers and expects commercialization of its hydrogen and renewable fuels infrastructure to expand significantly over the coming year.

The project brings together expertise from Mahle Powertrain, Phinia, BorgWarner, Cambustion, Hartridge and Oxford Brookes University to deliver the next generation of hydrogen combustion technology.

In related news, Volvo begins on-road testing of hydrogen ICE heavy trucks

Large utility vehicles significantly trail their passenger car counterparts when it comes to aerodynamic development. There are many reasons for this, including less stringent regulation, longer product cycles, poorly adapted resources and different customer priorities, but the winds of change have finally arrived.

Euro 6 regulations began pushing many larger vans into the category affected by the CAFE standards, and another significant step will be made with Euro 7 regulations set to take effect in 2027. Fierce competition is forcing OEMs to reduce their development cycles to stay competitive, while customers are being bombarded with information about the potential for operational cost reduction thanks to aerodynamically optimized vehicles.

Finally, with the December 2024 inauguration of the Automotive Test Section (ATS) at DNW’s Large Low-Speed Facility in the Netherlands, the large utility vehicle industry has a turnkey solution for precise aerodynamic measurement. In fact, the ATS is in complete accordance with the Worldwide Harmonized Light Commercial Vehicle Test Procedure requirements. This perfect storm of events will inevitably accelerate the shift toward more aerodynamically efficient utility vehicles.

When I was assigned as chief aerodynamic engineer on the new Renault Master project (XDD) in early 2018 – during the business strategy phase and just before the preconcept engineering kick-off – aerodynamic optimization for large vans was close to non-existent at the company. However, a competitor that had just won a coveted award was making a significant marketing effort to promote its world-class aerodynamic performance, which caught the attention of top management.

At the kick-off event a few weeks later, it was announced that the XDD Master would be the world’s most aerodynamic large van at launch. It was an incredible challenge. It took more than three years of focused teamwork to achieve the goal. Using a combination of competitor deep-dive analysis, hundreds of CFD calculations, around 200 hours of reduced-scale wind tunnel testing and regular intensive taskforce brainstorming, the general shape, engine cooling and exterior features were optimized. The achievement was confirmed during WLTP certification testing at DNW.

The result is a new Master large van family with 20% less drag and considerably reduced energy consumption. This means lower operating costs but also increased range and crosswind stability and, most importantly, without a negative impact on the vehicle’s utility, access, ergonomics or payload. The ‘advanced aerodynamics’ were specifically cited by the 25 international journalists that voted the new Renault Master IVOTY 2025.

While the XDD aero project can be considered a success at this point, the story continues with prep for Euro 7 certification. This month we will perform the first Master pre-Euro 7 certification testing using the wide-belt system for dual-wheeled utility vehicles. It’ll be a chance to test and perfect the Euro 7 aero package while also making our first use of the rolling resistance system in the ATS.

As I look back on my experience with this project, one subject particularly stands out: the issue of computer simulation versus physical testing. Clearly CFD will continue to gain importance and use as it is constantly improving. However, several large hurdles remain, which prevent an extremely accurate correlation with physical testing. The main limitation of CFD simulation is that it does not take into account model deformation.

At the 140km/h measurement speed of WLTP testing, things move a lot. Rubber air dams bend back, doors and hoods move outward, wheel arch liners and underbody panels vibrate, and the flexible air guides for engine cooling deform considerably. In addition, the tires and chassis change shape and position under the weight of the vehicle. None of this is taken into account by CFD, as the calculation burden would increase enormously.

In addition, utility vehicles have a huge wake compared with passenger vehicles, which accounts for a majority of the drag. A slight miscalculation in wake balance can have a large impact on the CdA result calculated by the software. Having compared a large number of wind tunnel tomography images and CFD wake calculations, I know that they are very similar but never identical. I believe a large part of the error in correlation I witnessed was caused by this discrepancy.

Therefore, I learned to use CFD for what it’s great at: visualizing the airflow. With CFD you can quickly detect early detachment at the rear, areas of localized turbulence and leaks in the air guides. There’s no better tool to explain to the architectural or design department why a change is needed. But when you need the precise drag value for a project milestone, or when it’s time to tweak the air dam or rear roof drop to balance the wake, you have to spend some time in the wind tunnel.

This thought leadership piece was published in the September edition of ATTI. Read the magazine online for free – it’s packed full of news, interviews and features, including how to maintain transparency in testing, the story behind the new Nissan Leaf, and the latest in battery testing and simulation

With more than 250 solution providers, The Future of Automotive Testing Conference and the Innovation Showcase, it’s the ideal place to discover new solutions, share ideas and build valuable connections.

There will truly be something for everyone, whether you’re an NVH specialist seeking new acoustics testing tools, an EV engineer in need of high-voltage test equipment, an ADAS expert looking for the latest lab systems, or a simulation specialist in need of a tool or a test driver searching for a new vehicle rental partner.

The Innovation Showcase will take place on day one and day three, enabling visitors to learn more about some of the latest technologies on display. Its interactive format is always a big hit. On day two, ATTI will host The Future of Automotive Testing Conference, beginning at 9:55am with an onstage interview featuring ATTI columnist Jon M Quigley, and with a program that features a wealth of influential industry figures.

Serving as the testing sector’s foremost communications platform, ATTI will also report live news throughout the show and gather intelligence for upcoming magazine issues. Don’t hesitate to share your ideas or news with ATTI.

For a comprehensive preview, see the September edition of Automotive Testing Technology International magazine.

Automotive Testing Expo North America will take place at the Suburban Collection Showplace in Novi, Michigan, on October 22-23. Visit the expo website to register for your free expo pass.

The Future of Automotive Testing Conference

This day of high-level content will explore various topics and provide an engaging opportunity to learn from and connect with industry peers. Situated among the exhibits, it will have a relaxing atmosphere, and visitors will be able to dip in and out at their leisure. A highlight will be ATTI’s on-stage interview with Jon Quigley, who worked for Volvo for many years and now runs his own company, Value Transformation. With his broad experience and portfolio of contacts, he’s a very good person to know. He loves sharing his thoughts, too, hence his new gig as ATTI’s regular columnist.

Read Quigley’s latest column on p36 of the September issue.

Also during the conference, Venkat Adusumalli, software engineering manager at Stellantis, will reveal how Stellantis is using AI to accelerate E/E system testing and validation workflows. Click here for a pre-show interview with him.

Innovation Showcase

The free-to-attend Innovation Showcase also provides an interactive platform for learning about new technologies. Speakers will welcome questions and discussion after their presentations, making it a great way to explore ideas together. Like the conference, it will take place within the main hall, so it will be very easy to listen in while wandering through the exhibits, or to come and go throughout the day.

Technology debuts

The industry is moving quickly and it can be a challenge to keep up. Every year there is an abundance of new technologies on display. Some are incremental improvements to existing products, others are entirely new. It’s always surprising how companies find ways around bottlenecks. Often, these developments emerge from ongoing conversations between supplier and customer, ultimately benefiting multiple companies.

Read ATTI‘s comprehensive expo preview in the September issue.

Face-to-face discussions  

It sounds obvious, but the most fruitful conversations are usually the ones that happen in person – it’s how journalists find the best stories. Year after year, exhibitors and visitors report having forged unexpected collaborations at the show, in the form of technology tie-ups or service partnerships.

Detroit’s revival 

A lot of money has been plowed into Detroit in recent years, as evidenced by the stunning renovation of Michigan Central Station, which is well worth a visit. Much of the investment has been in the tech sector. Eleven years ago – when the station was still derelict – ATTI took a tour of some of the labs at GM and what was then the FCA headquarters (see The right wave length, November 2014, Seasonal highlights, September 2015, and Powerbase, March 2015). The facilities were impressive then and are even more so now, thanks to several years of investment in innovation leading to Detroit’s resurgence as an automotive powerhouse.

Visit the Automotive Testing Expo North America website to secure your FREE pass, which will give you access to the expo, the Future of Automotive Testing Conference and the Innovation Showcase

Horiba’s Infra-Red Laser Absorption Modulation (IRLAM) technology marks a major breakthrough in infrared gas analysis. By combining advanced sampling techniques with next-generation computational algorithms, it delivers precise and reliable measurements. This has led to the development of a new range of compact, interference-resistant measurement systems for laboratory and on-road applications.

“IRLAM was designed to maximize testing flexibility without compromising data quality,” said Darren Andrews, executive VP and GM at Horiba. “Our line-up of IRLAM-based products supports improved vehicle environmental performance and helps the automotive industry reduce emissions, even as electrification advances. By 2030, our product roadmap will expand to include additional gas species and applications.”

Extensive testing – both internal and published – has proved that IRLAM technology offers significant advantages in NOX measurement. It delivers improved data quality, enhanced accuracy, superior wet measurement, minimal interference, lower maintenance costs and consistent response times, all of which contribute to potential cost savings.

With the EPA’s guidance letter now issued, OEMs officially have the green light to use Horiba’s IRLAM-based analyzers for NOX measurement in vehicle and engine certification testing.

Impending emissions legislation in North America (EPA 27) and Europe (Euro 7), covering both NOx and CO₂ emissions, is pushing engine designers harder than ever before in the search for greater efficiencies. And separately, working from a 2019 baseline, the EU requires a vehicle-by-vehicle 45% reduction in CO₂ by 2030, a 65% reduction by 2035 and a 90% reduction by 2040, using the theoretical VECTO measuring tool, which takes factors including aerodynamics and tire rolling resistance into account, alongside engine fuel consumption and exhaust output, in calculating CO₂ emissions.

As seen at IAA 2024 in Germany, the market take-up of battery-electric trucks has not been as quick as had been hoped because infrastructure development is behind schedule. Focus has shifted to improving the performance of internal combustion engines and associated systems with manufacturers now looking for incremental reductions in fuel consumption across the entire vehicle from fuel injection to tire rolling resistance. This search will take them beyond their own R&D resources and into proprietary solutions offered by third-party suppliers.

Theoretical work and laboratory testing can only go so far in determining the efficacy of any proposed modification. Particularly where third-party suppliers are concerned, both truck manufacturers and their customers want verifiable proof that the product can deliver worthwhile improvements in a working environment. The problem is that real-life testing will inevitably include external variables that may exaggerate or conceal performance improvements. Weather and traffic density are two obvious factors, but other variables, including the human factor of driver behavior, are harder to define and more difficult to manage. The ‘signal’ of verifiable and repeatable change must be separated from the ‘noise’ of external factors.

This was the challenge facing Cummins Valvetrain Technologies (CVT) in verifying the on-road performance of its Jacobs Cylinder Deactivation (CDA) – a technology with the potential to reduce fuel consumption and CO₂ emissions while also improving the efficiency of NOx SCR (selective catalytic reduction) control systems in low engine load conditions.

The theory behind CDA is simple. Most trucks are over-powered for the work in hand, most of the time. A 506hp tipper truck needs all that power when it pulls a full load up a quarry haul road but perhaps only half of that when returning empty to reload. Taking one, two or three cylinders out of six out of play has the potential to reduce fuel consumption in light-load conditions with little impact on productivity.

Jacobs’ system uses its hard-won expertise in valve control to automatically shut down selected cylinders in low engine load conditions by leaving their inlet and exhaust valves closed throughout the four-stroke cycle, while their fuel-injectors are also deactivated. This reduces fuel burn, and the parasitic pumping losses from needlessly filling and emptying the deactivated cylinders. When additional engine braking is required, the same components that deactivate the cylinders are re-purposed to provide vehicle retardation using the latest 1.5-stroke High Power Density version of the Jake Brake compression-release engine brake.

While the benefits of this are obvious on paper, quantifying them is rather more difficult. CVT chose the SAE J1321 standardized fuel consumption test with fully-loaded trucks on two routes: one highway and one distribution, on public roads in North America.

The tests were conducted using a 2018 International LT625 6×4 tractor unit with a 13-liter Navistar A26 450hp diesel engine and Eaton Endurant 12-speed overdrive AMT gearbox, both with a gross vehicle weight of 66,000 lb. Tests were run over 12,000 miles in Q4 2023 according to the SAE J1321 standard fuel economy protocol. The truck was run multiple times with and without CDA active, with the system engaged or disengaged via a dashboard switch. The truck recorded an average speed of 51mph on the highway route and 38mph on the distribution route.

Every run saw the test truck accompanied by a comparable control vehicle with its fuel consumption also recorded, to provide a baseline to account for variations caused by external factors such as weather and traffic conditions. Each route included trailer and driver swaps between the two trucks to eliminate those variables as far as possible.

The on-road, real-world results from a fully-loaded truck followed initial fuel economy improvements of up to 20% in dynamometer-based lab testing of an engine in idle mode. In that same lab test, 77% reduction in NOx was recorded on a low load cycle with a 2018 aftertreatment system. While NOx emissions testing was not a focus for this latest road test, the test trucks had the same calibration compliance to EPA 2018 standards, and CVT expects these results to further improve for future emissions requirements where the benefits of CDA thermal management are further used.

Results from the road tests indicated fuel savings of 2.76% on the highway route and 2% on the distribution run; this figure may appear low in relation to the lab test, but CDA will always yield the greatest savings in idling, over-run and low-load conditions. The real advantages of CDA are likely to become more apparent in conditions where the payloads carried vary from run to run.

CDA saves fuel by reducing the number of active cylinders to match the drivers’ real-time torque demand. The active cylinders have higher loads and temperatures, while the inactive cylinders have reduced parasitic losses. The reduced air flow, and air fuel ratio in the remaining active cylinders, helps maintain exhaust system temperatures above the critical 250°C mark to allow efficient NOx conversion by the selective catalytic reduction module and continued passive regeneration of the exhaust particulate matter (PM) filter.

On the highway tests without CDA, temperatures in the truck’s SCR unit fell below 250°C for over 15% of the journey time, but when CDA was used in concert with the Jacobs Engine Brake, SCR temperatures fell below 250°C only during the scheduled stops and trailer swaps. On the distribution route, the mean temperature of the SCR unit was 243°C with CDA engaged, compared to 16°C lower without cylinder deactivation.

Time spent with the SCR operating under 250°C was reduced by over 21%, and SCR temperature with CDA only fell below 200°C for under 2% of the time compared to over 10% of the time without.

Jacobs’ CDA systems can now be found in over 30 development programs, with engines ranging from 2-liter to 16-liter capacity, and some programs have advanced into vehicle testing stage.

Why is the US backing away from mandating EVs, which are good for both the industry and the planet? It’s a controversial question that will immediately attract criticism for being naïve about the benefits of BEVs and shielded by an academic’s isolation from the costly realities of a fragmented powertrain strategy. But look beyond the emotions and the USA’s approach is not only a sensible low-carbon strategy but could also ultimately secure the dominance of BEVs.

The challenge faced in the rollout of BEVs is shaped around the transition from the early adopters to the early majority. Those who are excited by the technology and by being in the vanguard of green passenger transportation are willing to overlook many of its current limitations. Those who just want to get around at an affordable price are proving to be less enthusiastic. Nothing will kill the transition faster than customer frustration, whether that is caused by an underdeveloped product, a challenging charging infrastructure, painful depreciation or soaring insurance premiums driven by poor repairability.

What the industry needs is breathing space to tackle these issues – and that’s what the USA has granted us.

There is a lot that we can do at a vehicle level to help overcome these challenges. Let’s start with batteries: they are heavy, very expensive and the supply chains are increasingly affected by rules of origin, for various reasons. Consequently, one of our jobs as research engineers is to minimize the battery capacity needed to achieve the overall vehicle performance goals. Add to that what one might call ‘charging anxiety’, and you have a compelling justification for a new generation of highly efficient, highly integrated hybrids.

It remains to be seen whether they prove to be a bridge to a fully electric future or retain relevance in their own right as fuels are decarbonized. Either outcome is a win if it helps the industry get to a sustainable position more quickly.

At IAAPS, we have always been enthusiastic supporters of a wide range of propulsion options – fully electric, hybrids and renewable-fuel vehicles including both hydrogen fuel cell and hydrogen combustion. This means we have maintained our internal combustion engine research and innovation capability while simultaneously investing in expertise and development resources for electric powertrains.

One exciting possibility is a new generation of hybrids that integrate an efficient, simplified ICE with a larger-than-usual electric drive. The engine can then be right sized for the majority of drive cycles without the need to include complex and costly technologies that would otherwise be required to extend the envelopes of power, torque and dynamic response. This enables us to get closer to the ideal of a single operating point ICE optimized for efficiency. The fuel that this engine will burn is an open question, with hydrogen a strong contender.

Delivering these (and other) low-carbon technologies efficiently will require significant progress in digital tools, especially for system-level decision making and the validation of complex systems with a large number of interactions. The growing focus on price, especially of BEVs, requires new approaches to be assessed and optimized, which requires a robust and highly efficient methodology.

At an individual system level, there is already an impressive range of proprietary tools available, but our work with industry shows that their capability often far exceeds the abilities of embedded processes to use them to deliver the promised savings. The result is a continuing reliance on experimentally intensive development and validation.

In other areas, the digital tools just aren’t good enough yet, either because the experimental data hasn’t been delivered or because the mechanisms are insufficiently understood. Battery modeling is a good example, especially around degradation – an area of research that is being greatly helped by over-the-air data from in-service vehicles.

Similarly with software control, it’s easy to enthuse about the software-defined vehicle but the complexity of validation required to explore the unknown unknowns has caused costly delays in several high-profile vehicle programs.

The much-publicized technology agnosticism of the new US regulations opens exciting new roadmaps for pragmatic powertrain strategies but also brings the challenges of greater technology diversity.

Let’s use this breathing space to take a step back and assess where we need to be and how we can get there as quickly and efficiently as possible. For many vehicle manufacturers, there is substantial competitive advantage waiting to be unleashed.

The sophisticated 738m², two-story facility is equipped with cutting-edge testing technology such as advanced simulation capabilities for road grades, load and wheel slip and robotic driving systems capable of handling both manual and automatic transmissions.

Jonathon White, VP of engine business engineering, emphasized the significance of the new facility: “This center enables us to develop and test a broader range of vehicles and machinery powered by hydrogen, renewable natural gas, advanced diesel or battery-electric. It is a key element of our destination zero strategy, aimed at reducing greenhouse gas emissions and improving air quality while aiding our customers in their transition to cleaner energy solutions.”

The facility represents a major upgrade for Cummins’ engineers, who are now learning how to harness the advanced dynamometers to analyze chassis-installed powertrains. This advance enables the development of full drivelines for a variety of applications, from compact SUVs and 44-ton trucks to double-decker buses and off-road machinery for construction and agriculture, with both two-wheel and four-wheel drive options.

White further noted, “Our extensive powertrain engineering expertise is driving the adoption of cleaner technologies, enhancing driveability, performance, efficiency and sustainability while keeping operational costs manageable. Additionally, the facility is designed to meet forthcoming regulatory standards, such as Euro 7 and CO₂  heavy-duty vehicle regulations.”

Each of the dynamometers features energy recovery systems that generate electricity for use across the Cummins site, reducing the strain on the local grid. The facility also utilizes rainwater harvesting to minimize water consumption, reflecting a system already implemented at the company’s engine plant.

Inside the facilities
Construction began in 2021 and the facilities were officially inaugurated in May 2024. State-of-the-art equipment within the new simulation center facilitates real-world analysis of vehicle functionality under extreme loads as well as virtual evaluation across diverse driving conditions. Temperatures from -7°C to +50°C can be replicated. Other conditions can also be simulated including 10% to 95% relative humidity (crucial for replicating regions such as India), sunlight exposure and mountain driving at altitudes of up to 5,500m above sea level.

One of the most important elements of the new asset is a modern roller dynamometer for vehicles with outputs up to 300kW, capable of emulating driving resistances at speeds of up to 265km/h. The resource is also equipped with sophisticated air ducting with two fans for airflow simulation, an emissions analysis system and a high-speed charging station for electric vehicles with outputs up to 400kW. Up to 850 tests can be conducted annually – greatly expanding the company’s capacity to devise new technical solutions.

An expansion of Škoda’s emissions lab in response to current and upcoming legislative requirements – namely Euro 7 – includes the installation of new measurement booths. These will primarily be used by the quality department to ensure that both preproduction and production vehicles comply with all relevant current and future global standards.

“Opening the new simulation center represents a significant step forward in automotive development and reaffirms Škoda Auto’s leading position in the evolution and testing of drive and thermal management systems. The importance of the new simulation center and the emissions center will continue to grow, both in terms of ensuring the quality of production vehicles and in creating highly efficient powertrains and systems for the future,” said Johannes Neft, board member for technical development at Škoda Auto.

There are currently numerous vacancies at Škoda Auto, which can be viewed on the company’s website.

Key data on the simulation center:
Construction timeline: October 2021 – May 2024 (890 days)
Building size: 550m²
Wiring: 35,420m connecting measuring technologies
Coolant volume: 45m³ in cooling circuits
Airflow: Approximately 20,000m³/h through ventilation units
Dynamometric rollers: Up to 300kW capacity
Maximum simulated speed: 265km/h
Highest simulated altitude: 5,500m above sea level
Sustained temperature range: -7°C to +50°C
Relative humidity range: 10% to 95%
Solar simulation: up to 1,200W/m²

The forum will be a vibrant hub where enthusiasts, experts and newcomers alike can converge to explore, share and connect on all things automotive testing and development. You can expect discussions on cutting-edge analysis technologies and industry trends, and passionate debates. The program will offer an afternoon of high-level content and will be followed by the first-ever live ATTI Awards ceremony.

Here’s what’s in store:

2:30pm
Welcome

2:40pm
Panel discussion – Exploring the future of automotive testing
Moderator: Dr Huw Davies, senior lecturer at Coventry University’s Centre for Future Transport and Cities

Gemma Hatton, freelance technical writer
Phil Durston, technical manager, Volkswagen
Nils Katzorke, project manager, Mercedes-Benz

3:20pm
In conversation

Jahee Campbell-Brennan, director, Wavey Dynamics
• AI-driven simulation is revolutionizing vehicle development
• How to gain actionable insights by using AI in testing
• The challenges in adopting AI-driven testing solutions

Plato Pathrose, CTO and technical director, ADAS and AD, Vinfast Germany
• The key hurdles of connected, software-defined and autonomous vehicle simulation
• How to formulate a successful simulation program
• Mature simulation platforms vs the latest collaborative platforms

4:00pm
ATTI Awards ceremony
Drinks and canapés will be served.

For more information, visit the Automotive Testing Expo Europe website.