John Deere is a leading American manufacturer of agricultural, construction, forestry and lawn care equipment. Founded in 1837 by John Deere, the company has grown to become a global icon in the field of heavy equipment and the engines they use.

Today, our focus will be directed towards their PowerTech line of engines, with particular attention given to the John Deere’s 4045 TIER 4 and the 6068 TIER 4 models.

John Deere’s 4045 engine derives its name from a specific designation following a nomenclature pattern established by the brand. The ‘40’ denotes the engine family (in this case, a 4-cylinder configuration), whereas the ‘45’ indicates the engine displacement in cubic centimeters. Likewise, the nomenclature of the 6068 follows a similar convention. It is categorized within the 6-cylinder engine family, with the ‘68’ representing the engine displacement in cubic centimeters. This nomenclature system allows for easy identification and classification of engines.


Tier 4, on the other hand, refers to the emissions regulations set by the US Environmental Protection Agency (EPA) for off-road diesel engines.

Below are the technical specifications of two of the most commonly used variants of both engines. The 4045CI 550 TIER 4 and the 6068 CI 550 TIER 4.

4045 CI 550 TIER 4 specifications:

  • Number of cylinders: 4
  • Displacement: 4.5 L
  • Bore and stroke: 106 x 127 mm
  • Compression Ratio: 17.2: 1
  • Engine type: In-line, 4-stroke
  • Aspiration: Turbo charged
  • Length: 867 mm
  • Width: 826 mm
  • Height: 987 mm
  • Dry weight: 575 kg
  • Standard: TIER 4 FINAL
  • Power rating: 93-129 kW (125-173 hp) @ 2200-2400 rpm
  • Maximum power: 93-129 kW (125-173 hp) @ 2000-2400 rpm
  • Maximum torque: 494-667 nM @ 1600 rpm
John Deere 4045


6068 CI 550 TIER 4 Specifications:

  • Number of cylinders: 6
  • Displacement: 6.8 L
  • Bore and stroke: 106 x 127 mm
  • Compression ratio: 16.7: 1
  • Engine type: In-line, 4-stroke
  • Aspiration: Turbo charged
  • Length: 1160 mm
  • Width: 768 mm
  • Height: 1144 mm
  • Dry weight: 750 kg
  • Standard: TIER 4 FINAL
  • Rated power: 168-224 kW (225-300 hp) @ 2200-2400 rpm
  • Maximum power: 185-224 kW (248-300 hp) @ 2200-2400 rpm
  • Maximum torque: 1000-1057 nM @ 1600 – 1700 rpm
John Deere 6068

Technological features

These are the technological features of the John Deere’s 4045 and 6068

Series turbocharger

Air is first drawn in by the low-pressure turbocharger and compressed to a higher pressure. The high-pressure turbocharger then draws in the compressed air, compressing it further. It then directs the high-pressure air through a charge air cooler to the engine’s intake manifold. By splitting the work between two turbochargers, both can operate at maximum efficiency and at slower rotational speeds, reducing stress on turbocharger components and improving reliability. In addition, series turbocharging provides more boost pressure than single turbocharger configurations, resulting in higher power density, better low-speed torque and improved high altitude operation.

Cooled exhaust gas recirculation (EGR)

Cooled exhaust gas recirculation (EGR) involves cooling and mixing precise amounts of cooled exhaust gas with incoming fresh air. This process aims to lower peak combustion temperatures, which contributes to the reduction of nitrogen oxides (NOx) levels.

Diesel Oxidation Catalyst (DOC)

PowerTech PWL 4.5-litre Tier 4 Final engines produce near-zero levels of particulate matter (PM) without a filter, thanks to an optimized combustion system and engine calibration. Remaining PM and other hydrocarbons are passively oxidized in a continuous flow DOC without the need for regeneration.

Selective Catalytic Reduction (SCR)

John Deere engines are fitted with an SCR system that uses a urea-based additive. The ammonia in the urea mixes with the engine exhaust gases in the SCR catalyst to reduce NOx, converting it to nitrogen and water vapor.

High pressure common rail fuel system (HPCR) and engine control unit (ECU)

The HPCR fuel system provides variable common rail pressure and high injection pressures. Moreover, it governs fuel injection timing and offers precise control over the start, duration, and end of injection. Additionally, it allows for adjusting the amount of fuel supplied to the engine, thereby enhancing efficiency and performance.

Here is a detailed guide to differentiate between the various models in the John Deere’s Power Tech 4045 and 6068 series. In this guide, you will find the variations in power, performance, emissions technology and dimensions of the different variants.

John Deere 4045 TIER 4

John Deere 4045

John Deere 6068 TIER 4

John Deere 6068
John Deere 6068
John Deere 6068
John Deere 6068


At Oryx Parts, as Maxiforce distributors in Europe, we boast a wide range of spare parts for the John Deere’s 4045 and 6068 serie´s . This includes pistons, valves, gaskets, camshafts, overhaul kits, and more.

Furthermore, at Oryx Parts, you will also discover parts for engines from renowned brands such as Kubota, Perkins, Yanmar, Deutz, Cummins, Caterpillar, and many others.

If you need to repair a John Deere engine, at Oryx Parts we ensure the success of your repair. We supply engine parts all over Europe – contact us!

Leave a Comment