the Model 'R' was designed against the CAT D-4 as a reference point.
It was suppose to sell into the market for heavy tillage in Western Wheat fields and out perform a D-4 Farm Cat in every respect possible. It was to be cheaper, faster, more economical to operate, and get more work done. Mission accomplished.
The Model R had a gasoline-fueled auxiliary starting engine, which eased two problems that had plagued earlier diesels. Most diesel tractors had been started by the operator standing on the ground, manually turning a flywheel; the Model R was started by the operator in his seat pulling a lever.
The difference between a battery start and a gas engine starter is that unlike the battery start, the longer you wrestle with it the easier it starts. This is because the goat engine shares a water jacket with the diesel and because the exhaust from the goat passes through a crude heat exchanger preheating the air entering the diesel.
The earlier diesel had been notoriously difficult to start; the Model R auxiliary starting engine enhanced warm-up; allowing fast start even in cold weather.