Cummins L9 engine: displacement, ratings and the trucks that use it

The Cummins L9 is an 8.9-litre six-cylinder in-line engine from Cummins Inc. Cummins’ sheet for fire and emergency vehicles gives its displacement as 540 cu in/8.9 L and its configuration as “Inline 6”, and Cummins’ truck bulletins of 2022 and 2024 give ratings from 260 to 380 hp (194 to 283 kW) with 860 to 1,250 lb-ft (1,166 to 1,695 N·m) of peak torque. The documents read for this page name three sets of emission rules for it: ADR80/04 in Cummins South Pacific’s bulletin, the EPA, CARB and Mexican NOM-044 rules in a Freightliner México sheet, and Euro 6 in BMC’s data sheets for the Tuğra construction trucks. The natural-gas version is the L9N. On this site the BMC Tuğra and the Freightliner M2 list the L9 among their engines.

Status as of 3 November 2026. Read that day: three Cummins documents on the L9 from Cummins’ media library, the truck bulletin of Cummins South Pacific (Bulletin 6440189, 11/22), the 2024 L9 bulletin of Cummins Inc. (Bulletin 6491592, Rev. 12/24) and its sheet for fire and emergency vehicles (Bulletin 4971542, Rev. 3/25). Freightliner México’s L9 sheet of November 2025 and Daimler Truck North America’s release of 9 March 2026 were read on 8 October 2026, and BMC’s Tuğra data sheets on 16 October 2026.

Maker, name and layout

Cummins names the engine L9 in all three of its documents read for this page: two from Cummins Inc. and the bulletin for Australia and New Zealand from Cummins South Pacific Pty Ltd. The truck bulletins of 2022 and 2024 speak of “35+ years of production with more than 5 million engines manufactured globally”, the fire and emergency sheet of “over 5 million L Series engines produced” and of 35 years. The ratings are named by their advertised horsepower, from L9 260 to L9 450. Daimler Truck North America lists the natural-gas version as the “L9N (natural gas)”. BMC’s data sheets name the Euro 6 engine “Cummins ISL9E6E (Euro 6)” on the TGR 3540 DXD and “Cummins L9E6E (Euro 6)” on the TGR 3540 TXT and 4340 DXD; the Cummins documents read for this page use neither form and do not explain them.

Cummins’ truck bulletin of 2022 says the single module aftertreatment combines SCR, “a redesigned dosing unit and a DPF into a single flow-through unit”, and that the electronic control module gives “fully integrated control over the engine and aftertreatment system”. What the law requires of SCR systems and their reagent is covered in SCR and AdBlue.

Ratings as Cummins states them

Cummins’ truck bulletins of 2022 and 2024 give the L9 as 260-380 hp (194-283 kW) with a peak torque of 860-1250 lb-ft (1166-1695 N·m), at a governed speed of 2100/2200 rpm. Cummins South Pacific’s bulletin lists eight ratings, which it groups as “380-370 HP Performance Ratings” and “360-260 HP Productivity Ratings”; Freightliner México’s sheet of November 2025 prints the same eight ratings with the same figures.

Cummins’ sheet for fire and emergency vehicles lists eight ratings, from the L9 270 to the L9 450, with the speed of each.

The two Cummins documents print different figures for three ratings: the L9 380 has 1,250 lb-ft (1,695 N·m) in the truck bulletin and 1,150 lb-ft (1,559 N·m) in the fire and emergency sheet, the L9 370 has 276 kW in the first and 275 kW at 2,100 rpm in the second, and the L9 300 has 224 kW and 223 kW. The fire and emergency sheet speaks of “tens of thousands of Cummins L9 engines” in the fire service and describes a “fire pump governor interface”; fire engines built on truck chassis are covered in fire engines on truck chassis.

BMC’s data sheets give the Euro 6 L9 in the Tuğra construction trucks (TGR 3540 DXD, TGR 3540 TXT and TGR 4340 DXD) as 400 PS (298 kW) at 2,100 rpm with 1,700 Nm at 1,400 rpm, and list a 252 kW engine brake as standard. The fire and emergency sheet gives engine braking of “Up to 350 hp @ 2600 rpm”; engine brakes are described in retarders and engine braking. How kW, hp and PS relate is explained in reading truck power figures.

Versions and dates in the documents

None of the documents read gives the year the L9 entered production or dates the “next generation L9” beyond the bulletin’s own date, 11/22. Daimler Truck North America’s release of 9 March 2026 covers the engines of its “upcoming 2027 products”: it says the Cummins X10, a clean-sheet design, is “engineered to replace both the L9 and X12 engines”, and lists the “L9N (natural gas)” among the established Cummins platforms that “will continue into the 2027 lineup” across a range of Freightliner and Western Star trucks. The release gives no date for the end of the L9 diesel.

Fuels and emission class

• Diesel. BMC’s sheets give the type as “Turbo Intercooler Dizel”; Cummins’ truck bulletin of 2022 describes a high pressure common rail fuel system and an aftertreatment module with SCR and a DPF.
• Biodiesel. The fire and emergency sheet gives a biodiesel compatibility of “Up to B20”. None of the documents read mentions HVO, the renewable diesel described in what is HVO fuel.
• Natural gas. The gas version is the L9N, which Daimler Truck North America lists as “L9N (natural gas)”; none of the Cummins documents read for this page covers it.

Cummins South Pacific’s bulletin states “The L9 meets ADR80/04 emissions standards.” Freightliner México’s sheet says the L9 meets the requirements set by the US Environmental Protection Agency (EPA), the California Air Resources Board (CARB) and the “NOM-044 mexicana”. BMC’s sheets mark the engine Euro 6 without naming the Euro VI step; the steps from Euro VI A to E and what Euro 7 adds are covered in Euro VI and Euro 7. The 2024 L9 bulletin and the fire and emergency sheet name no emission standard.

Trucks and buses on this site with the Cummins L9

The model pages below list the Cummins L9 among their engines. The figures are those of each model’s own page and of the source that page cites, in kilowatts and newton-metres as the site’s records keep them; they are not the engine-level tables above.

The Peterbilt 579 page records its engines in its notes, in the maker’s units, and is not in the table; among them is the natural-gas Cummins L9N, at 8.9 l and 320 hp.