If you need proof to see just how far four-cylinder engine technology has come in recent times, then it’s worth looking at Valtra’s N163. Its maximum output? A whopping 126kW/171hp. But could this be a power step too far for shorter wheelbase tractors? We find out with a test of Valtra’s Direct CVT model.

INo replacement for displacement? That was the traditional thinking when it came to engines. But over the years we’ve seen manufacturers squeeze more power from smaller capacity motors, and, as part of this trend, four-cyl tractors have been upping their game; no doubt they’ll soon be knocking on the door of 200hp. Valtra has been at the forefront of this race, and, proving the point, its current N163 four-cylflagship boasts statistics of 126kW/171hp/169PS from a 4.9-litre block.

The AGCO Power (or Sisu for diehard Valtra fans) 49AWI-4V unit incorporates electric common-rail injection, four valves per pot and a combination of a Diesel Oxidation Catalyst and SCR using AdBlue to meet Stage IIIB or Tier 4i, depending on which side of the Atlantic you reside. Rated output should be 117kW/159hp/157PS using the ISO14396 standard and then boost to 126kW/171hp/169PS when Sigma Power engages.

To put some meat on our tractor test bones, first stop for our N163 Direct was the DLG dyno, where the rated speed result reached 94.6kW/129.0hp/127.4PS at the shaft, and the boosted results hit 116.4kW/158.0hp/156.1PS. That’s excellent data. The increase in power is attributed to the engine’s power curve, which plots a torque rise of nearly 52% while engine speed drops by only 27%, and there’s a constant power band of nearly 32%. Max torque of 666Nm represents a new four-cylinder record.

But to generate power you need to burn juice, and the N Series does this at 262g/kWh at rated speed and 239g/kWh at max pto output — both average results. In addition to diesel the tractor consumes 15g/kWh of AdBlue. Similar results were obtained during the drawbar power measurements with 316g/kWh at rated and 273g/kWh at max output — relatively high fuel rates for a Stage IIIB-compliant model.

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