Cummins B6.7 engine: displacement, ratings and the trucks that use it

The Cummins B6.7 is a 6.7-litre six-cylinder in-line diesel engine from Cummins Inc. Cummins’ specification sheets B6.7-G17 and B6.7-G18, both dated April 2020, describe its G-Drive version, for which they also list typical generator-set outputs: an “Inline 4-Cycle Diesel, Turbocharged & Charge Air Cooled” with a bore and stroke of 107 x 124 mm, designed “to meet EU Stage V, and US Tier 4 Final emissions”, with gross outputs from 131 to 237 kWm at 1,500 and 1,800 rpm. On this site it is one of the engines of the BMC Tuğra, whose page records it as the Cummins ISB6.7, and of the Freightliner M2.

Status as of 26 October 2026. Read that day: Cummins’ specification sheets B6.7-G17 and B6.7-G18 (both 04/2020) from Cummins’ media library, and the engine records of this site’s model pages. None of the documents read is a Cummins sheet for the B6.7 in a truck or bus.

Maker, name and layout

Both sheets carry the line “Cummins is a registered trademark of Cummins Inc.” and name the engine B6.7, with the suffixes G17 and G18 for the two G-Drive models. The model records on this site use two names for the family: “Cummins B6.7” on the Freightliner M2 page and “Cummins ISB6.7” on the BMC Tuğra page. The Cummins sheets read for this page use only “B6.7” and do not explain the ISB form.

The two sheets print the same general engine data apart from the fuel rating code, FR97284 on the B6.7-G17 and FR97283 on the B6.7-G18, and differ in their ratings and in their fuel and DEF consumption figures.

Ratings as the maker states them

Each sheet gives a gross and a net engine output in kWm and BHP for three duties, standby, prime and base, at 1,500 rpm (50 Hz ratings) and at 1,800 rpm (60 Hz ratings).

The duties are defined on the sheets in electrical terms. Prime Power (PRP) is “Applicable for supplying power to varying electrical load for unlimited hours”; Base Load (Continuous) Power (COP) is “Applicable for supplying power continuously to a constant electrical load for unlimited hours”; Emergency Standby Power (ESP) covers “the duration of power interruption of a reliable utility source”. Beside the engine output the sheets list a typical generator set output, from 111 kWe (B6.7-G17, base, 1,500 rpm) to 205 kWe (B6.7-G18, standby, 1,800 rpm), and fuel and DEF consumption at each load step.

The sheets give no torque figure. How kW, hp and net power are defined for road vehicles is explained in reading truck power figures.

Dates and versions in the documents

Both sheets carry “©2020 Cummins Inc.” and the date in their codes, “B6.7-G17 (04/2020)” and “B6.7-G18 (04/2020)”. They present “The new Cummins G-Drive engines” as “designed with next generation aftertreatment technology”. Neither sheet dates the first B6.7 or names an earlier version, and none of the documents read for this page gives a dated history of the B6.7 in trucks or buses.

Fuel and emission class

• Fuel. The sheets give the type as “Inline 4-Cycle Diesel” with a Bosch HPCR fuel system, and list DEF consumption beside fuel consumption for each rating. Neither sheet mentions HVO, the renewable diesel described in what is HVO fuel, or a gas version.
• Emission class. Both sheets are headed “EU Stage V and Tier 4 Final” and describe an “Integrated Aftertreatment Design” with a “Full single module (DOC/DPF/SCR)”, an “EGR-Free Design”, an intake throttle “for increased thermal management capability” and an “Aftertreatment specification capable of low load operation up to -25º C.” Neither sheet names a Euro VI step; the Euro VI steps for road vehicles and what Euro 7 adds are covered in Euro VI and Euro 7.

Trucks and buses on this site with the Cummins B6.7

Two model pages on this site list the Cummins B6.7. The figures below are those recorded for the engine on each model’s own page; they are not the G-Drive ratings above.