JB23 Type 4 25-Year Rule: Which Manufacture Months Become US-Eligible in 2027｜Month-by-Month Unlock Table

Published 2026-08-31 ・ 21 min read ・ Japan Vehicle Data

Type 4 JB23 Jimnys manufactured in January 2002 become eligible for US import in January 2027 — 25 years after they left the factory. But Type 4 production ran from January 2002 through September 2004, which means eligibility is not a single date. It is a rolling window that stretches from January 2027 to September 2029.

As of August 2026, every Type 4 JB23 is still ineligible. The first cars clear five months from now. Understanding which manufacture month your specific car carries is the difference between shipping it in early 2027 and waiting until 2029.

This article covers: why the 25-year clock runs on manufacture month, what the Type 4 production window is and how we know it, the full month-by-month eligibility table for all 33 months of Type 4 production, what the chassis number does and does not tell you about build date, two methods to pin down your specific car’s manufacture month, and how Type 4 fits in the broader 2027 import cohort. The full mechanics of how the 25-year rule works under 49 CFR Part 591 are covered separately; this article focuses on the Type 4 JB23.

This article is not customs or legal advice; confirm timing with your importer and customs broker.

Type 4 JB23s unlock starting January 2027 — but only January 2002 builds clear that month

The US 25-year exemption under 49 CFR Part 591 runs from the month of manufacture, not the model year and not the first registration date. A JB23 Type 4 built in January 2002 becomes eligible in January 2027 — 25 years later, same month. A Type 4 built in September 2004 becomes eligible in September 2029.

This distinction matters more for Japanese cars than for almost any other market. Japan does not use model years the way the US does, and the JB23 was sold continuously under the same designation for nearly twenty years. “JB23 Type 4” tells you the revision, not the calendar year, and the revision spans almost three years of production. The phrase “Type 4 unlocks in 2027” — common on import forums — is technically correct for the first month of Type 4 production, but it is misleading for any car built after December 2002. The majority of Type 4s do not unlock in 2027.

The practical implication: if you are evaluating a Type 4 JB23 for purchase, the manufacture month is as important as the chassis number. Two cars with consecutive chassis serials may have meaningfully different eligibility dates.

Type 4 production ran January 2002 through September 2004 — chassis 310001 to 399999

Type 4 (4型) is defined by two boundaries in the JB23 chassis number sequence. It begins at chassis JB23W-310001 in January 2002. It ends where Type 5 begins: JB23W-400001, which carries an October 2004 start date confirmed across multiple independent Japanese registries.

This places the final Type 4 chassis in the range ending at 399999, with the last units rolling out in September 2004 — the month immediately before the October 2004 Type 5 transition. The gap between the last Type 4 and first Type 5 chassis numbers (399999 to 400001) leaves no ambiguity about the type boundary.

The headline change that defines the Type 4 is mechanical and visual: the bonnet and grille separated into two distinct pieces (replacing the single-piece front end of Types 1–3), and the intercooler was enlarged with low- and mid-range torque improved. It is still squarely pre-facelift JB23. The Type 5 transition in October 2004 — the switch from a mechanical 4WD lever to push-button selection, plus a completely redesigned dashboard — marks the more significant generational break.

Source note: The chassis number ranges and corresponding start dates are cross-referenced across two independent Japanese chassis registries and agree exactly. The start of Type 5 at JB23W-400001 in October 2004 is confirmed by multiple sources; one otherwise-reliable registry incorrectly lists January 2002 for Type 5 (clearly a transcription error). We use October 2004. Detailed comparison of all ten revision types is at JB23 revision types.

The month-by-month 2027 eligibility table: January 2002 builds unlock January 2027, September 2004 builds unlock September 2029

This table covers all 33 months of Type 4 JB23 production. Eligibility dates are derived from the 25-year rule under 49 CFR Part 591: the US eligibility date is exactly 25 years after the manufacture month. All dates are as of August 2026.

2002 builds — unlock throughout 2027

2003 builds — unlock throughout 2028

2004 builds — unlock throughout 2029

Precision note: Sources differ on whether eligibility opens on the first day of the 25th-anniversary month or on the exact calendar anniversary date. The practical difference is small but real — do not schedule a vessel to arrive in the opening days of your unlock month. Leave schedule slack. This article is not customs or legal advice; confirm timing with your importer and customs broker.

What this means in practice: Only Type 4s built in calendar year 2002 — roughly the first third of Type 4 production — unlock within 2027. If you are planning a 2027 import specifically, you need a car with a January–December 2002 manufacture date. Type 4s built in 2003 and 2004 require patience until 2028 and 2029 respectively.

Your chassis number tells you the type — but not the manufacture month

The JB23 chassis number format is JB23W- followed by a six-digit serial. The serial places you within the type sequence, but it does not encode the manufacture month. There is no year digit or date digit in the JB23 chassis number.

What the chassis number does tell you: if your serial falls between 310001 and 399999, you have a Type 4. Anything above 400000 is Type 5 or later. That type identification is reliable and important — it determines the eligibility window you are working within (January 2027 to September 2029).

What the chassis number does not tell you: where within that 33-month window your specific car sits. Two Type 4 JB23s with serials 310050 and 395000 are both confirmed Type 4s, but their manufacture dates could be separated by more than two years. The serial number progression is roughly linear through production, but irregular pauses in production, batch sequencing, and variant assembly mean that sequential serials do not map cleanly to sequential months.

For the full breakdown of what distinguishes each revision type — mechanical changes, parts compatibility, and the chassis number boundaries for all ten types — see JB23 revision types.

Two methods to pin down your specific car’s manufacture month

This is the most important practical section. Because the chassis number does not encode a manufacture date, you need a separate source. Two methods are reliable, and both draw on primary records.

Method 1: The compliance plate (door jamb plate)

The most direct evidence is a build date plate attached to the vehicle at the factory. On the JB23, this is typically a small riveted or adhesive-backed plate located in the door jamb area (driver’s side B-pillar or door sill). It records the manufacture date — sometimes in Japanese Imperial calendar notation.

Japanese Imperial calendar years in the Type 4 period translate as follows: Heisei 14 (H14) = 2002; Heisei 15 (H15) = 2003; Heisei 16 (H16) = 2004. A plate reading “H14.03” means March 2002.

The plate is the most direct evidence, but it requires physical access to the car. If you are evaluating a car remotely or the plate is damaged or missing, Method 2 can corroborate or substitute.

Method 2: MLIT recall database cross-reference

Japan’s Ministry of Land, Infrastructure, Transport and Tourism (MLIT) publishes every recall with chassis number ranges tied to production periods. The database is publicly available at https://carinf.mlit.go.jp/jidosha/carinf/ris/search.html.

The process:

1. Navigate to the MLIT recall search page.
2. Enter the vehicle model information (JB23W / Jimny).
3. Review the recalls that appear. Each recall lists the affected chassis number range and the corresponding production period (the dates during which those chassis were manufactured).
4. Find recalls where your car’s chassis serial falls within the listed range.
5. The production dates associated with that recall range bound your car’s manufacture period. If multiple recalls with overlapping ranges apply, the intersection gives you a tighter bound.

This method works because MLIT recall records are built from manufacturer-submitted chassis-to-production-date mappings — the same data that establishes which cars need to be fixed. The MLIT recall cross-reference method is explained step by step here.

Which method to use: If the compliance plate is readable and accessible, use it — it is the most direct answer. The MLIT method is best used to corroborate the plate or to establish a manufacture period when the plate is unavailable. For customs purposes, having both is stronger than either alone.

What CBP accepts as manufacture date evidence — and why the MLIT method is strong

CBP’s evaluation of a vehicle’s import eligibility under the 25-year rule centers on the manufacture date, not the registration date or the model year. When the manufacture date is disputed or the vehicle lacks an immediately readable factory document, CBP looks at what evidence supports the claimed date.

The MLIT recall method is a strong entry in this hierarchy for a specific reason: it is derived from manufacturer-submitted government records. When a recall is issued in Japan, the manufacturer provides MLIT with precise chassis-to-production-date data. That data is not an approximation — it is the same data Suzuki used to identify which cars needed to be remediated. When you establish your car’s manufacture period through MLIT recall cross-reference, you are citing a government database built on manufacturer documentation.

The compliance plate is also strong evidence, but it requires physical inspection and (where the date is in Imperial calendar notation) translation. The MLIT method can provide corroborating documentation that a licensed customs broker can present with the import filing.

CBP’s own guidance on importing a car is available at https://www.cbp.gov/trade/basic-import-export/importing-car. The full mechanics of the 25-year rule — including what CBP accepts as evidence and the asymmetry that can save you a port hold are covered in the pillar article.

A note on NHTSA and EPA. The 25-year rule exemption covers NHTSA Federal Motor Vehicle Safety Standards compliance. EPA emissions exemptions have separate rules and timelines. Confirm both with your licensed importer and customs broker before committing to a shipping schedule.

Type 4 in context: where it sits in the 2027 cohort alongside the R34 and RX-7

2027 is the year when some of the most-watched JDM chassis begin clearing the 25-year threshold. The R34 GT-R, the FD3S RX-7, the A80 Supra, and the S15 Silvia all ended production in August 2002 — meaning those chassis are fully eligible from September 2027 onward. The JB23 Type 4 is a different kind of car, but it enters the 2027 conversation for one historically specific reason.

The Type 4 JB23 holds a specific position in JB23 history: it is the last revision to retain the mechanical 4WD lever. Type 5 (October 2004) replaced the lever with push-button selection, along with a complete dashboard redesign. For buyers who specifically want the lever-operated 4WD system — which some off-road users prefer for its direct mechanical engagement — the Type 4 is the final available option among models that will unlock in the 2027–2029 window.

The Type 4’s production window (January 2002 to September 2004) means it straddles the 2027, 2028, and 2029 eligibility years. Unlike the R34 and FD3S, which close out entirely in August 2027, Type 4 JB23s will be clearing for nearly three years. The complete 2027 eligibility calendar — covering the R34, FD3S, A80 Supra, Evo VII, Type R, and more — is here.

Frequently asked questions

Q1. Does “Type 4” mean all cars built in that revision unlock at the same time?

No. “Type 4” identifies the revision specification — the set of changes Suzuki made to the JB23 at that point in production. The type ran from January 2002 through September 2004, which is 33 months of production. Each month of manufacture unlocks 25 years later. January 2002 builds unlock in January 2027; September 2004 builds do not unlock until September 2029.

Q2. My car has chassis number JB23W-3xxxxx — how do I find the manufacture month?

The “3” prefix confirms you are in the Type 4 range (310001–399999). However, the chassis number does not encode the manufacture month. Use the compliance plate in the door jamb (which records the factory build date, sometimes in Imperial calendar notation) or cross-reference your chassis serial against the MLIT recall database to bound the production period. Both methods are described in the H2-5 section above.

Q3. What is the difference between the manufacture month and the first registration date?

The manufacture date is when the car was assembled at the factory. The first registration date is when the car was formally registered with the Japanese transport authority — which can be weeks or months later, and occasionally more than a year later if the car sat in dealer stock. The 25-year rule runs from manufacture date. The Japanese shakken (inspection) document and the vehicle registration certificate record registration date, not manufacture date. Do not use first registration date to calculate US eligibility.

Q4. Can I use the Japanese shakken (inspection) document to prove the manufacture date?

The shakken document is not manufacture date evidence. It records the inspection date and registration history. CBP requires evidence that ties to the factory build date — the compliance plate or corroborating records such as MLIT recall data. A licensed customs broker familiar with JDM imports can advise on what documentation package is appropriate for your specific car.

Q5. Is a January 2027 delivery possible for a January 2002 build?

In principle, yes — a car confirmed manufactured in January 2002 crosses the 25-year threshold in January 2027. In practice, there is uncertainty about whether CBP treats eligibility as opening on the first day of the month or on the exact anniversary date. If your car’s manufacture date is January 15, 2002, some readings of the rule would place eligibility on January 15, 2027. Do not book a vessel to arrive in early January 2027 for a January 2002 car. Leave scheduling slack. Confirm the precise timing with your importer and customs broker.

Q6. Does the 25-year rule apply to all US states equally?

The federal 25-year exemption under 49 CFR Part 591 is uniform across all states for NHTSA compliance purposes. However, registration and emissions requirements vary by state. California, for example, has its own emissions framework and does not automatically accept federally-eligible imported vehicles. Confirm state-level registration requirements with your importer before purchase.

Limitations

The following limitations apply to this article:

1. Chassis number boundary is community-established, not a Suzuki publication. The Type 4 chassis range (JB23W-310001 to 399999) is documented in Japanese enthusiast registries cross-referenced across multiple independent sources. Suzuki has not published an official English-language type-by-type chassis number guide. The data is internally consistent and widely referenced, but it derives from community records rather than a manufacturer document.

2. Type start date is not necessarily the first manufacture date. The January 2002 date for Type 4 reflects when the revision designation changed in production. The first units of a new type may not have been produced on the first of the month — pre-production, tooling changeover, and initial batch runs mean the actual earliest Type 4 build date could be mid-month or later. This does not affect eligibility calculations for cars where the compliance plate or MLIT records confirm a specific month, but it means that January 2002 as a type start date is the revision transition point, not a guaranteed first-day-of-month production date.

3. CBP eligibility date precision is unresolved. Whether eligibility opens on the first day of the 25th-anniversary month or on the exact calendar anniversary date is not uniformly confirmed across CBP communications. The difference is practically small for most shipping logistics but could matter if a vehicle’s compliance plate records a mid-month manufacture date. Do not assume day-one eligibility.

4. No monthly production volume data. The table above covers all 33 months of Type 4 production, but no public source provides a breakdown of how many units were manufactured in each month. Some months likely had higher output than others; the table does not reflect volume, only the eligibility date for any car manufactured in that month.

5. This is not legal or customs advice. Import eligibility involves NHTSA, EPA, CBP, and state-level considerations beyond the 25-year age threshold. Consult a licensed importer and customs broker for your specific vehicle.