Mazda is developing a CO₂-negative combustion engine, deliberately positioned against the trend of full electrification. The goal is a powertrain that, theoretically, binds more carbon dioxide than it releases. This concept combines climate protection with existing technology and brings the combustion engine back into focus. At the same time, however, a key conflict emerges: a politically motivated ban on combustion engines threatens to stifle precisely such innovations at an early stage. (it-boltwise: 15.12.25)
Why Mazda is sticking with the combustion engine
Mazda justifies its approach with global realities, as energy supply, charging infrastructure, and economic conditions vary considerably. A CO₂-negative combustion engine allows the company to continue using existing vehicles, production lines, and refueling networks while still improving its emissions balance. This is precisely why the manufacturer is not opting for a radical break, but rather for technological advancement.
The engine is part of a hybrid system, with an electric motor providing targeted support to the combustion engine. This allows the drive system to operate more frequently in its optimal efficiency range, reducing fuel consumption and emissions. This combination forms the basis for a technology that goes beyond conventional efficiency improvements.
CO₂ Capture Directly in the Vehicle
At the heart of the concept is a special module in the exhaust system. This system filters carbon dioxide from a portion of the exhaust gas and stores it in the vehicle. Mazda currently reports a capture rate of around 20 percent. The CO₂-negative combustion engine thus differs fundamentally from conventional engines because emissions are not only reduced but also physically captured.
This form of CO₂ capture occurs while driving and not via external compensation models. This creates a measurable effect that technically redefines the combustion engine and places it in a different category.
Biofuels as a Key Factor
In addition to capture, the fuel used plays a crucial role. Mazda is focusing on biofuels that absorb carbon dioxide from the atmosphere during their production. When this fuel is burned in a CO₂-negative combustion engine, CO₂ is produced, but some of it was previously captured, while some is recaptured.
In the overall balance, this can result in a negative CO₂ value, at least theoretically. Mazda sees this as a realistic transition because existing infrastructure can continue to be used. This approach is gaining importance, especially in regions with weak charging infrastructure.
Political Directives as a Brake on Innovation
This is precisely where a fundamental conflict arises. An ideologically driven ban on combustion engines imposed by politicians ignores technological developments such as the CO₂-negative combustion engine. Instead of defining emission-based targets in a technology-neutral way, a specific type of drive system is excluded from the outset.
This puts research and investment under pressure, even though they could make measurable contributions to climate protection. Innovations that genuinely reduce or even sequester emissions lose their economic viability if their use is politically prohibited. Mazda’s approach demonstrates that climate targets can be achieved without blanket bans.
Costs and Technical Complexity
Mazda nevertheless openly acknowledges the challenges. Additional separation modules increase weight, installation space requirements, and maintenance, while production costs also rise. Critics therefore doubt its suitability for mass production because a CO₂-negative combustion engine must remain price-competitive.
However, the manufacturer points to earlier technologies such as catalytic converters or hybrid drives, which were also initially considered expensive. With increasing production volumes, costs could decrease as the technology matures. However, a regulatory framework that doesn’t prematurely preclude such developments remains a prerequisite.
Why Mazda’s Approach is Changing the Debate
The CO₂-negative combustion engine challenges a central assumption: climate neutrality doesn’t necessarily mean abandoning the internal combustion engine. Mazda demonstrates that conventional drive technology can be further developed to not only reduce emissions but also actively capture and store them.
It remains to be seen when this technology will be ready for mass production. However, it’s clear that blanket bans limit technological progress. If innovations like this are prevented, the industry loses potential solutions. This is precisely why Mazda’s approach is not only technically relevant but also of fundamental political importance.