When John Deere launched the 8R series tractors last year, the company claimed the series broke the horsepower record in row-crop tractors. (See "2011 guide to new 150-plus-hp row-crop tractors," with specifications and photos at "Specs for new 150-plus-hp row-crop tractors.") Well, now it’s official. The second largest model, the 8335R, recently underwent dynamometer testing at the Nebraska Tractor Test Lab and measured in at a record-breaking 306.6 PTO hp in the rated engine speed PTO test.

“This is the first row-crop tractor ever tested in Nebraska that breaks the 300-rated PTO horsepower barrier,” says Chad Hogan, division marketing manager, Waterloo Tractor Works.

The largest of the series, the 8360R, is being tested now and is expected to rate even higher than the 8335R.

The Nebraska Tractor Test Lab also measured fluid efficiency. The 8335R was found to deliver 15.45 hp hrs./gal. in the 75 percent of pull at maximum power drawbar test, which is up to 28 percent higher than the 8320R model it replaced.

The fluid efficiency rating is significant for Deere because the 8335R is equipped with a new Tier 4 emission-compliant engine (See "John Deere reveals plans for Tier 4 engine.") The company says the rating is proof that its single-fluid engine emissions technology, called Exhaust Gas Recirculation (EGR), does not sacrifice performance in meeting the new emissions standard, which took effect in January.

Complete results of the test can be found at tractortestlab.unl.edu/testreports.htm.