Komatsu D37-23 and D39-23 crawler dozers have been upgraded with Tier 4-Interim SAA4D95LE-6 diesels that cut fuel consumption by up to 10 percent over predecessor models while retaining the same horsepower ratings: 89 and 105 horsepower, respectively, at 2,200 rpm. Operating weights range from 18,386 to 21,363 pounds, depending on configuration and model. Long track EX and low-ground-pressure PX models are available.