Having a 400hp tractor equipped with a CVT in your range seems to be a growing trend, with several manufacturers now offering such machines. James Rickard checks out New Holland’s latest offering with an on-farm test.
While Agco has well established CVT tractors from three of its stables, most notably the Fendt Vario, last year also saw Claas join the club with the introduction of the 900 series. This year, it is the turn of Case IH and New Holland. We put the latter through its paces with a rigorous on-farm test.
Our test model was the range-topping T8.420 AutoCommand, producing a maximum of 420hp from its Stage 3b, FPT motor.
The new AutoCommand range comprises six models ranging from 275hp to 420hp. These models effectively mirror the UltraCommand (powershift) versions which the firm offers, with the exception of the additional 420hp flagship.
From the outset, the CVT versions do not look too dissimilar to the UltraCommand models they compliment. However, a closer look reveals a few subtle differences, most of which are due to the tractor now having to accommodate a CVT and the increase in power. This includes a 100mm longer wheelbase and a beefier back-end which features a 127mm (five inch) diameter bar axle, which can handle 900/60 R42 tyres. As a result on the top two models, the pto assembly, drawbar and three-point linkage arms have been extended so implements clear the larger tyres.
Another new feature is the in-house made front axle and suspension assembly (formerly Dana Spicer), which is now a simpler ‘saddle’ type, says the manufacturer.
To see what the T8 was made of, we attached it to a Great Plains SLD 460 - a seven leg, 4.4m working width cultivator with two rows of discs and a set of DD consolidating rings.
Providing traction at the rear was a set of Michelin AxioBib IF 710/75 R42 (upgraded from the standard 710/70R 42 MechXBib) pressurised to 0.8bar, which Michelin says produces the same footprint as its 800/70 R38s. Up-front on the linkage, a 1,600kg Lynx Engineering weight block kept the nose in check.
To achieve infinite speed selection, the T8 AutoCommand uses four mechanical range gears coupled to a hydrostatic swash plate pump, very similar to the transmission used in the smaller T7s.
New Holland’s T8 market support specialist, Mark Howell says, “Having the T8 AutoCommand in our range now lets us offer customers more transmission options, and should appeal to people who want the convenience of selecting infinite speeds for jobs such as potato bed preparation, mowing or drilling for example.”
For those unfamiliar with the T8 series it features a generously sized, five-post cab – the extra/odd post is required for the door – with good access to a lofty driving position. From the seat, visibility is good all-round for such a large tractor, giving the illusion that it is smaller than it actually is.
A noticeable feature is that the dash is incorporated into the right-hand A post, rather than behind the steering wheel – a concept which takes a while to get used to but is actually quite user-friendly, with priority information organised at the top such as fuel, temperature and revs, and secondary information lower down such as transmission status, hydraulics and linkage position. Also, much of the information (if specified) is duplicated on the IntelliView IV touch screen terminal (which ours came with). A smaller IntelliView III screen (standard) or both screens together can be specified, if for example you wanted to control tractor and implement functions on one and monitor GPS guidance on the other.
The screen is mounted on the armrest which also accommodates the main CommandGrip control lever which takes care of all primary functions including transmission, hydraulics and headland management and auto-steer activation.
Working to a depth of 200-250mm (8-10 inches), the sticky Lincolnshire clay really gave the tractor something to think about, perfectly highlighting how the transmission and engine work together to achieve optimum performance.
In cultivation applications especially, the engine and transmission will always try and keep the revs down and the speed up to cover the most amount of ground, in the quickest way, using the least amount of fuel it can. And compared to its powershift equivalent we were impressed. In our conditions it was managing to achieve a target speed just shy of 10kph at 1,750rpm, consuming about 65l/hour of fuel. That roughly equates to a fuel consumption of 14.8l/hectare.
The CVT is controlled by the main, return-to-centre type, lever on the armrest. Further and finer adjustment comes from a scroll wheel just under your right thumb. The scroll wheel can also set desired target/cruse speed, of which you get three. We generally selected a speed for working, a speed for headland turns and one for the road. These three speeds can be quickly toggled between using the same buttons which the UltraCommand uses to shift gears.
As for the four mechanical ranges previously mentioned, you can forget about these as they automatically and seamlessly switch between each other without you hardly noticing.
Three different transmission reaction levels can also be selected via a button on the armrest. Depending on how you like it, the transmission can react quickly to changing conditions, almost instantly altering revs and speed to suit conditions. This is most apparent at the headlands - when you first drop the cultivator in the engine roars into life while low gear ratios are selected. This is shortly followed by the engine settling down and with gear ratios increased to achieve desired target speed.
Another feature of the transmission is automatic hill hold. For example, if you pull up to a set of traffic lights on a hill, up or down, and come to a stop, the transmission will hold the tractor in position, even if loaded. If it is for longer than 30 seconds, the automatic park brake will kick in. To pull away, you just need to apply pressure to the travel pedal and away you go again, without having to re-engage anything.
You can also set lower rev limits via the throttle lever and the upper rev limit/droop via a knob on the armrest. This is useful for pto applications where you need to maintain constant revs. But for towing a cultivator, it easier to just let the tractor’s wizardry get on with it.
On the road, it picks its feet up quickly, although the travel pedal is quite sensitive, so a gentle foot is required. Thanks to its suspension and low pressure tyres it soaks the bumps up well. It also managed to achieve 50kph at 1,400rpm, helping the fuel bill.
While the UltraCommand versions are well suited to heavy cultivation work, by mechanically transferring all of their power to the ground via a powershift transmission, we wondered how the CVT would fair in comparison.
However, the AutoCommand exceeded all expectations in terms of productivity, especially when it came to cultivating.
Despite the extra length, the AutoCommand is remarkably agile for its size, making headland turns easier without having to skip bouts. And considering the tractor was fresh out of the box, the engine was pretty lively too.
Overall, the AutoCommand offers a quality driving experience which should provide some good competition to the CVT stalwarts.