Caterpillar now offers a differential-steer option on a smaller sized track-type tractor—the new D6N. Both the D5N and D6N not only retain the strengths of the D5M and D6M, but also include an electronic engine that increases horsepower, improves fuel efficiency and reduces emissions; a quieter, more comfortable operator's station; new styling; and serviceability improvements. Both machines are powered by the Cat 3126B HEUI engine. The D5N and D6N are equipped with Finger Tip Control (FTC) steering. The D6N also has a differential-steer option, which maintains power to both tracks while turning, so large blade loads can be maneuvered efficiently. Estimated list prices for the D5N: $134,000 to $147,000; D6N: $188,000 to $215,000.