Isuzu 4JZ1 engine: 2,999 cc diesel, versions, ratings and trucks

The Isuzu 4JZ1 is a diesel engine of 2,999 cc that Isuzu Motors introduced in Japan on 20 March 2018 in the ELF, its light-duty truck, first for the versions above 7.5 tonnes gross vehicle weight. Isuzu’s release of that day calls it a newly developed “小排気量高過給エンジン” (in this site’s translation, a small-displacement, highly boosted engine) with its main components renewed, and pairs it with a DPD and urea SCR aftertreatment to meet Japan’s Heisei 28 exhaust emission regulations; Isuzu’s English Tokyo Motor Show 2019 page says the engine achieved compliance with Japan’s Post Post New Long Term (PPNLT) emissions standards. Isuzu’s documents name two versions: the 4JZ1-TCS at 110 kW (150 PS) and, from 22 May 2018, the 4JZ1-TCH at 129 kW (175 PS). Isuzu later fitted the 4JZ1 to the ELF hybrid (30 May 2019) and to the N-Series of the full model change announced on 7 March 2023. On this site the Isuzu N-series records it.

Status as of 26 October 2026. Seven Isuzu Motors documents were read on 26 October 2026: five Japanese-language releases on the ELF (20 March 2018, 22 May 2018, 29 October 2018, 30 May 2019 and 22 January 2024), Isuzu’s English release on the N-Series and F-Series of 7 March 2023, and Isuzu’s English exhibition page for the Tokyo Motor Show 2019. Quotations from the Japanese releases are given in Japanese with this site’s translation. Power is given as Isuzu prints it, in kilowatts with metric horsepower (PS) in brackets; how the units relate is explained in kW, hp and Nm: how to read a truck’s power figures.

What the 4JZ1 is

Isuzu Motors Limited calls the 4JZ1 newly developed, and in the documents read it appears only in Isuzu’s own trucks. Isuzu’s Japanese releases call the truck ELF (エルフ); its English release of 7 March 2023 calls the range the N-Series and names its battery-electric models ELF EV. The same model code, 2TG-NJR88AF, appears with the 4JZ1-TCS in that English release and in the Japanese ELF Space Cab release of 22 January 2024.

Isuzu’s Tokyo Motor Show 2019 page links the engine to the 4JJ1, part of Isuzu’s D-CORE diesel engine series, which it says “was developed for ELF 2007 model onwards”, and continues: “With ELF 2018 model, D-CORE further evolved and became a basis for the new engine 4JZ1, specially developed for commercial vehicles.” The base data below are as Isuzu’s documents state them; a dash means none of the documents read gives the item.

The documents read do not explain the suffixes TCS and TCH, and none of them names HVO, biodiesel or gas operation for the 4JZ1.

The release of 29 October 2018 names technologies adopted with the engine, among them fuel injection quantity feedback control (燃料噴射量フィードバック制御), a variable exhaust valve phasing system (排気位相可変バルブ) and model-based EGR control (モデルベース EGR 制御). The Tokyo Motor Show 2019 page adds that the engine’s package layout makes it possible to position the “Diesel Particulate Defuser (DPD)”, as Isuzu names it there, “close-coupled to the engine”.

Emission class

The Isuzu documents read give the 4JZ1 a Japanese emission standard only. The release of 20 March 2018 says the ELF models above 7.5 tonnes gross vehicle weight met the 平成28年排出ガス規制 (the Heisei 28 exhaust emission regulations) through “新型4JZ1エンジンの搭載と後処理装置の改良” (fitting the new 4JZ1 engine and improving the aftertreatment). Isuzu’s English Tokyo Motor Show 2019 page says the engine achieved “compliance to the Japan’s Post Post New Long Term (PPNLT) emissions standards” and describes it as “A new engine 4JZ1 fitted with urea SCR”. How urea SCR works, and what European law makes such a system detect, is set out in SCR and AdBlue.

The release of 30 May 2019 calls the 4JZ1 “平成28年度排出ガス規制に対応したエンジン” (an engine meeting the Heisei 28 emission regulations). None of the Isuzu documents read gives a Euro class for the 4JZ1; the European steps are a separate system, explained in Euro VI (Euro 6) and Euro 7 for trucks.

Versions and dates

Isuzu’s documents do not divide the 4JZ1 into generations. The dates below are those of the releases in which the engine, or a new application of it, appears; the model codes and outputs are those of the models each release prices.

Introduction (20 March 2018). Isuzu’s release says the ELF models above 7.5 tonnes gross vehicle weight received the new 4JZ1 engine, describes it as “主要コンポーネントを一新した新開発の小排気量高過給エンジン 4JZ1(排気量2,999㏄)” (a newly developed small-displacement, highly boosted engine with renewed main components, 4JZ1, displacement 2,999 cc) and gives the DPD + urea SCR aftertreatment. Its priced model is the 2RG-NPR88YN with the 4JZ1-TCS at “110kw(150PS)”.

Second rating (22 May 2018). “既存の4JZ1-TCS(最高出力150PS)に加え、新たに4JZ1-TCH(最高出力175PS)を展開しました” (in addition to the existing 4JZ1-TCS, maximum output 150PS, the 4JZ1-TCH, maximum output 175PS, has been introduced). A footnote limits it to “ワイドキャブのMTのみの展開” (the wide cab with a manual gearbox only). The priced model lists the 4JZ1-TCH at “129kw(175PS)”.

Revised ELF (29 October 2018). The release describes the 4JZ1 with the technologies named above, its 2,999 cc displacement and the DPD and urea SCR, and prices the 2RG-NPR88AN with the 4JZ1-TCS at 110kw(150PS).

Hybrid (30 May 2019). Isuzu says it fitted the hybrid ELF with the 4JZ1, which it describes as fully renewed with fuel injection quantity feedback control among its technologies. The priced hybrid, the 2SG-NJR88AN, is listed as a diesel hybrid with the 4JZ1-TCS at 110kW(150PS).

Full model change of the N-Series (7 March 2023). Isuzu’s English release introduces “The 9-speed dual-clutch (DCT) transmission named Isuzu Smooth Intelligent TransMission (ISIM)”, which it calls “a newly-developed Automated Manual Transmission (AMT)”, offered with the 4JZ1 (how such gearboxes work is explained in Automated manual transmissions). Its priced model, the 2TG-NJR88AF, has the 4JZ1-TCS at “110kW(150PS)” with “ISIM(9-speed AMT)”.

ELF Space Cab (22 January 2024). The specification table of the Space Cab release gives the engine type as 4JZ1-TCS, the displacement as 2,999cc and the transmission as ISIM (9速AMT), on the 2TG-NJR88AF.

The documents read do not say whether or when the 4JZ1 will be replaced, and the releases of 2019, 2023 and 2024 list only the 4JZ1-TCS; whether the 4JZ1-TCH was offered after 2018 is not stated in them.

Ratings as Isuzu states them

None of the Isuzu documents read gives a torque figure or the engine speed at which the output is reached. The only torque on this site for the engine is the one in the Isuzu N-series record below, which comes from that page’s own source.

Trucks and buses on this site with the Isuzu 4JZ1

One model on this site records the 4JZ1, a truck; no bus on this site records it. The figures are those of the model’s own page and of the source that page cites, in kilowatts and newton-metres as the site’s records keep them.