Internal-Combustion Engines Patents: Top Companies & Trends 2026
- 20.6% concentration at the top. The five leading assignees account for 37,210 of the 181,055 records in scope — a dense core surrounded by a long tail of smaller filers.
- Filing volume has pulled back. Filings fell from 324 in 2021 to 209 in 2024, a 35% drop over that three-year span, even before the most recent, still-incomplete years are excluded.
- Engine control dominates the claim map. F02D (engine control) alone touches 5.8% of all records, more than fuel supply, exhaust treatment or valve gear combined on a per-class basis.
Filing growth compares 2021 (324 records) with 2024 (209) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 181,055 records in scope (CR5), not by the ranked leaders only.
A mature field with a shrinking filing rate
Internal-combustion engine patenting is one of the deepest and oldest fields in mechanical engineering, and the record volume reflects it: 181,055 published records sit inside this search scope, spanning core combustion architecture, fuel delivery, ignition, exhaust treatment and the control software that ties them together. The dataset is dominated by incremental control and calibration claims rather than new combustion chemistry, which is consistent with a technology base that automakers and tier-one suppliers have been refining for decades rather than reinventing.
Filing activity has been declining across the most recent complete years, and the leading assignees are almost all automotive OEMs and their component suppliers rather than pure combustion specialists. That pattern points to a field where claim space around core engine architecture is heavily occupied, and where the more interesting open questions are in adjacent control, emissions and hybridisation claims rather than the base internal-combustion engine itself.
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Filing trend and technology composition
Publication lags filing by roughly 18 months, so the last one to two years in any chart understate true filing activity; treat the tail as incomplete rather than as a real decline.
Filings pulled back through the most recent complete years
Filings ran at 672 in 2017 and peaked at 683 in 2018, then declined; the clearest comparable window is 2021 (324) to 2024 (209), a 35% drop, taken as the most recent pair of years both largely complete.
Engine control and fuel supply lead the IPC composition
F02D (engine control) covers 5.8% of the 181,055 records in scope, ahead of F02M (fuel supply and carburettors) at 3.5% and F02B (internal-combustion engines proper) also at 3.5%. Exhaust treatment (F01N), separation processes (B01D), valve gear (F01L), ignition (F02P) and cooling (F01P) each sit below 2.5%, indicating those branches carry comparatively less filing pressure per record.
Shares are the percentage of the 181,055 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Internal-Combustion Engines Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about internal-combustion engines patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this field
Controller and control method for internal combustion engine (US20170284323A1)
Filed by Mitsubishi Electric, this application targets a known weak point in EGR (exhaust gas recirculation) control: calculation error in recirculated exhaust gas amount caused by component ageing and intake-air humidity changes, including during transient operation. It calculates a humidity-detecting EGR rate from intake-air and manifold humidity, then derives an opening area that realises the target recirculation flow rate from that rate.Abstract trimmed for length; full claims available via the linked record.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20090020958A1 | Methods and apparatus for operating an internal combustion engine | 1,460 |
| 2 | US4106446A | Internal combustion engine with auxiliary combustion chamber | 1,419 |
| 3 | US6276334B1 | Premixed charge compression ignition engine with optimal combustion control | 406 |
| 4 | US6026921A | Hybrid vehicle employing parallel hybrid system, using both internal combustion engine and electric motor for… | 343 |
| 5 | US5628186A | Method and apparatus for controlled introduction of a reducing agent into a nitrogen oxide-containing exhaust… | 334 |
| 6 | US5272871A | Method and apparatus for reducing nitrogen oxides from internal combustion engine | 334 |
| 7 | US6230683B1 | Premixed charge compression ignition engine with optimal combustion control | 327 |
| 8 | US6170443B1 | Internal combustion engine with a single crankshaft and having opposed cylinders with opposed pistons | 309 |
| 9 | US5327987A | High efficiency hybrid car with gasoline engine, and electric battery powered motor | 304 |
| 10 | US20040035401A1 | Hydrogen powered scooter | 299 |
Citation counts favour older filings simply because they have had longer to accumulate citations inside this corpus — read them as a signal of influence on later filers, not as a marker of current importance.
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Browse MCP servers →What the numbers say about where this field is headed
Three patterns stand out once concentration, filing trend and class composition are read together.
The top of the field is dense, the rest is a long tail
The five leading assignees hold 20.6% of all 181,055 records in scope, rising to 28.4% for the top ten. That leaves the majority of filings spread across the remaining ranked entrants, which is typical of a technology where OEMs and their direct suppliers file defensively across the whole engine platform.
Volume is contracting, not merely levelling off
Filings dropped from 324 in 2021 to 209 in 2024. That decline predates the most recent, still-incomplete publication years, so it is not an artefact of publication lag — it reflects a real pullback in new filing activity across the leading assignees in this window.
Control logic, not combustion chemistry, is the busiest claim space
F02D (engine control) touches more of the record base than any other subclass, ahead of fuel supply and the core internal-combustion-engine class itself. Filing pressure is concentrated in calibration, sensing and control-loop claims layered on top of largely settled mechanical architecture.
Filing is US-anchored with a modest PCT and European tail
The United States receives more than double the filings of the EPO (5,156), with WIPO/PCT, the UK, Canada and Australia trailing well behind. That skew suggests most applicants are prioritising domestic protection first and filing selectively abroad.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to internal-combustion engines patent landscape, with the prior art for and against each one.
Who is filing, and where the momentum has gone flat
The ranked leaders are almost entirely automotive OEMs and their tier-one suppliers, and recent-year momentum for several of the largest names has dropped to zero or near it — consistent with the field-wide filing pullback rather than any one company stepping back alone.
A single assignee well ahead of the field
The leading assignee holds 15,668 records, well clear of fifth place at 4,438 and tenth place at 2,136 — a steep drop-off that marks a genuine gap between the top filer and the rest of the ranked field.
Corporate-group co-filing is concentrated, not widespread
Only 10 co-assignee pairs appear in the data, with the strongest pair sharing 92 records — consistent with internal group filing between a parent and its captive component or engineering subsidiary rather than open cross-company collaboration.
Several top filers show zero output in the latest year
Multiple assignees among the largest historical filers, including some of the ranking's most prolific names, show 0 records in the latest year with year-on-year changes as steep as -100%. Read this alongside the 18-month publication lag: it likely overstates the real slowdown, but the multi-year 2021-to-2024 decline is independently confirmed.
| Assignee | Recent year | YoY |
|---|---|---|
| Honda Motor Co., Ltd. | 1 | -50% |
| Toyota Motor Corporation | 0 | -100% |
| Nissan Motor Co., Ltd. | 0 | -100% |
| Hitachi, Ltd. | 0 | — |
| Denso Corporation | 0 | — |
| Robert Bosch GmbH | 0 | -100% |
| Ford Global Technologies, LLC | 0 | — |
| GM Global Technology Operations LLC | 0 | -100% |
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is freedom-to-operate, licensing or R&D prioritisation.
Map claim scope inside F02D before filing
With engine control claiming 5.8% of all records, a new control-logic filing needs a tight freedom-to-operate check against the leading assignees' control and calibration claims before drafting.
Run a claim-scope check in EurekaWatch the leading assignee's post-2024 filings closely
The gap between the leader and fifth place is wide enough that any shift in that assignee's filing rate will move the field's overall trend on its own.
Track assignee activity in EurekaTest white-space claims in under-claimed branches
Sub-areas like transient EGR humidity compensation and seal-clearance control show thinner filing density than the core classes, worth validating before committing R&D budget.
Explore white space in EurekaFrequently asked questions
The ranking is led by a single assignee with 15,668 records, well ahead of the field — fifth place holds 4,438 and tenth place 2,136. The leaders are almost all automotive OEMs and their major component suppliers rather than combustion-technology specialists, reflecting how deeply engine control and fuel-system claims are tied to whole-vehicle platforms. The gap between first and fifth place is large enough that the leader's own filing rate materially moves the field-wide trend.
No — filings fell from 324 in 2021 to 209 in 2024, a 35% decline over that span, and the field peaked back in 2018 at 683 filings. The most recent one to two years in any chart will look even lower, but that reflects the roughly 18-month lag between filing and publication rather than a further real drop. Taken together, the multi-year trend through the last complete year shows genuine contraction, not just an artefact of recent incomplete data.
Engine control (F02D) is the busiest IPC subclass, touching 5.8% of the 181,055 records in scope, ahead of fuel supply and carburettors (F02M, 3.5%) and core internal-combustion engine architecture (F02B, 3.5%). Exhaust treatment, separation processes, valve gear, ignition and cooling each sit well below that, at 2.3% or less. Because records often carry multiple IPC classes, these percentages describe filing density per class against the full record base, not a breakdown that sums to 100%.
The classes with the thinnest filing density relative to the core engine-control and fuel-supply areas — valve gear, ignition systems and engine cooling, each under 1% of records — are worth a closer look, alongside specific sub-areas like transient-state EGR humidity compensation and seal-clearance control in variable-geometry actuators. Thin filing density in a sub-area does not guarantee an easy grant, but it does mean fewer blocking claims to design around. Any white-space claim still needs a freedom-to-operate check against the leading assignees' broader control-system patents.
Moderately concentrated at the very top, with a long tail below it: the five leading assignees hold 20.6% of all 181,055 records in scope, rising to 28.4% for the top ten. That leaves more than 70% of filings spread across the remaining ranked entrants and the unranked field beyond them. It is a field with a clear leadership tier but not a monopoly — smaller filers still hold the majority of the record base.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.