top of page

Cummins 4BT 3.9L Engine (Design, Reliability & Tuning)

Updated: Feb 2

✔ This article has been fact checked.

The Cummins 4BT is a water-cooled inline four-cylinder turbocharged diesel engine from the Cummins B series, it produces around 105 hp and 360 nm of torque.

It was initially intended for use in industrial, commercial, and agricultural applications.

  • First generation engines produce 105 hp and 265 lb-ft of torque.

  • Second generation 4BTA engines have four valves per cylinder and deliver 170 hp and 420 lb-ft of torque.

  • 4BT engines are also fairly fuel efficient for their age, delivering around 15-20 mpg.

The most common Cummins B series engines are the 3.9L inline-four and 5.9L inline-six models, four-cylinder engines of 3.3L and 4.5L are also available.

Table of Contents:

Cummins 4BT 3.9L Engine