This summer the local electric co-op was trimming/clearing their line along our western property line. I was talking to their forestry/procurement manager while we were looking at their chopper. It was BIG, could handle up to 18" stuff.

He said that they were all gas now after decades of diesel models. The gas simply do a better job now, are less expensive to buy, and have less maintenance and repair costs. Took them all by surprise, but they have had the gas ones for several years now and are not going back to the diesels. Surprised me too.