Cummins ISB 6.7L Engine Specs, Problems & Reliability

Cummins ISB 6.7L Engine

Here in this post, I have gathered information about the Cummins ISB 6.7L Engine from its official website, including its specifications, Problems, and Reliability.

We believe in providing reliable information to our readers, therefore we prefer to obtain information on the Cummins ISB 6.7L Engine from authentic sources.

This article, which has been updated, has all the information you require about the Cummins ISB 6.7L Engine.

Cummins ISB 6.7L Engine

The most recent and largest model in Cummins’ B series, the ISB 6.7 L, is a straight-six turbodiesel engine.

With 350 horsepower and 650 pound-feet of torque, the ISB 6.7 is Cummins’ most potent diesel engine for light and medium-duty trucks.

Firing order 1-5-3-6-2-4
Engine oil weight
SAE 15W40 diesel oil
Engine oil capacity, liter 12 qts (11.4 liters) with filter.
Oil change interval, mile 15,000 (24,000 km) or 6 month (7,500 miles or 6 months for 2007.5 – 2012 model years).
Applications Dodge Ram pickup trucks, buses, medium duty trucks
Manufacturer Cummins
Production years 2007- current
Cylinder block material Cast Iron
Cylinder head material Cast Iron
Fuel type Diesel
Fuel system Direct injection, electronically controlled Bosch high pressure common rail injection.
Number of cylinders

Valves per cylinder 4
Valvetrain layout OHV
Bore, mm
4.21 inch, 106.9 mm
Stroke, mm

4.88 inch, 124 mm
Displacement, cc 408 cubic inches, 6.7 liters
Type of internal combustion engine
Four-stroke, turbocharged
Compression Ratio

17.3 : 1
Power, hp
305-385 hp /2,800-3,000
Torque, lb ft
610-900 lb-ft (827-1220 Nm)/1,500-1,700
Engine weight

1050-1150 lbs, 476-522 kg, dry

Cummins ISB 6.7L Engine Problems & Reliability

The 6.7 ISB has improved upon previous Cummins B engines in terms of dependability. Failure rates are low when stock is purchased B engines in terms of dependability.

Failure rates are low when stock is purchased. Emissions control devices and Common Rail fuel injection systems are notoriously problematic.

All engines with an EGR system suffer from the same problem of the system being clogged. The DPF has a lifespan of around 100,000 miles.

Aftermarket DPF delete kits are preferred by some drivers due to their lower price, although they are not environmentally friendly.

Remember that the VGT does not like to sit idle for lengthy periods of time. Maintenance on the fuel injectors of an ISB6.7 is also required at 200,000 miles.

Owners have noted that the 6.7 version’s injectors are more reliable than those found in the 5.9 model.

Cummins ISB 6.7L Engine Review 

Cummins ISB is a turbocharged, intercooled diesel engine in production since 2007. The Cummins ISB 6.7L engine is popular for medium-duty trucks and buses. It can also be used in heavy-duty applications. For a full review, please check this YouTube video Here.

Cummins ISB 6.7L Engine FAQ

What does ISB mean for Cummins?

One of the largest straight-six engines used in light truck vehicles and school buses is the 5.9 L, 359.0 cu in (5,883 cc) ISB (Interact System B); the upgraded high-output 600 version was included in Ward’s 10 Best Engines list in 2004.

Is the 6.7 Cummins a good engine?

The Ram 2500 and 3500, powered by the legendary 6.7-liter Cummins diesel engine, are unrivaled on paper.

It’s a really powerful package, with 400 horsepower and 1,000 pound-feet of torque. Since its introduction in 2007, the Cummins engine has been quite successful for Ram.

What problems does the 6.7 Cummins have?

The exhaust gas recirculation (EGR) system, clogged diesel particulate filters (DPFs), and blown head gaskets are all problems that are more common with the Cummins 6.7L diesel engine.

What fuel mileage does a 6.7 Cummins get?

There are two available engines for the 2022 RAM 2500: a 6.7-litre Cummins® Turbo Diesel Inline-6 and a 6.4-litre HEMI® V8 that together generate up to 410 horsepower and 429 pound-feet of torque in 4×4 form.

In four-wheel drive mode, the engine can achieve a fuel economy of up to 12 mpg in the city, 18 mpg on the interstate, and 15 mpg overall.

Is the 6.7 Cummins twin turbo?

Any vehicle powered by a 6.7 Cummins Twin Turbo will be efficient, quiet, and mighty under load. developed to perform superbly with any horsepower level, from stock to 600.

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