14 April 2000

STABLEMATES WEIGHED UP…

Choosing a new tractor can often involve comparing

models from the same manufacturer, as well as from

different ranges. Peter Hill weighs up how tractors of the

same horsepower weigh up against their counterparts

WITH tractor manufacturers trying to meet as many different tastes and requirements as possible, there is inevitably some overlap between the top end of one range and the bottom end of another.

In this comparison, the decision has already been taken on the amount of power needed. The task is to find what compromises might result from opting for a tractor from the lower end of a manufacturers range. And what the extra cash brings from buying the equivalent horsepower model from further up the line.

Buyers looking at supposed lesser models certainly do not get short-changed these days. For example, the added convenience of power shuttle forward-reverse selection has moved down into this sector, as has multi-speed semi-powershift gearboxes and electronic linkage control in some cases.

There is also significantly more choice in this sector, reflecting the fact that buyers are more often working to a strict budget than to a pre-determined specification. Quite apart from the fact that buyers wanting a utility tractor often have no call for a lot of the sophisticated features found on specced-up models.

A low-profile cab, shaving a few millimetres off the tractors overall height – potentially crucial for those with old-fashioned low doorway barns – is also the province of the "utility" tractor.

Otherwise, the main differences are to be found in overall weight, transmission sophistication, hydraulics performance and, to some extent, engine power and torque characteristic, even though rated power output may be the same.

New Holland TN75…

… New Holland TL80.

Case-IH CX90…

…Case-IH MX90C.

New Holland TN75 versus TL80

THE 72hp TN75 is clearly a smaller, lighter tractor than its TL80 bigger brother. Yet this little machine packs a lot of features into its small package, especially when its the tight-turning SuperSteer version.

The TN-series machine is the newer design, and is assembled in Italy, while the TL (until recently designated L/35 series) owes a lot to former Fiat designs. Though production started in Italy, it is now put together at New Hollands Basildon plant.

Specification differences kick off with very different engines from the same manufacturer. The TL80s Iveco 8000-series motor is an unblown four-cylinder, 3.9 litre unit. It develops 75hp at 2500rpm and 266Nm of maximum torque at 1400rpm. Torque rise is an average 25%.

The TN unit is a more highly charged three-cylinder turbo motor of 2.93 litres. Power at a lower revving 2300rpm is 72hp, but the turbo and fuel injection profile results in more maximum torque than the TL80 can muster at 295Nm at 1500rpm. Torque rise is an impressive 36%.

Add to this a weight advantage to the smaller tractor of between 515kg and 575kg before any ballast weight or optional equipment is added, and the TN75 should be a sprightly performer.

The TN model runs on a wheelbase that, in the case of the conventional front axle models, is up to 245mm (9.6in) shorter than the TL80s. That suggests it would pitch more over rough ground, although a lower centre of gravity will help in this respect.

Go for the SuperSteer version, however, and the TN75 takes on a stretched look with a wheelbase of 2375mm that puts the front axle very nearly ahead of the tractors nose. It needs to go this far forward to allow the sideways axle movement and extra-tight steering angle that is translated into a 480mm (19in) turn radius advantage over the TL80.

The bigger tractor scores when it comes to linkage lift capacity, at 3210kg or 4450kg at the ball ends depending on whether the optional auxiliary lift cylinder is fitted. The TN75 musters 2670kg but is up to the mark in terms of hydraulic oil flow with a few litres/minute in hand over the TL80s output at 46 litres (standard) and 67 litres (optional).

Its not an issue for some but the TN75 can also be had with electronic linkage control and its various functions (including diff lock linked to linkage lift/lower and implement damping), which is denied UK buyers of the TL80.

Nor does the TL hold any advantage in the transmissions department, as the TN is more than adequately equipped with a choice of gearboxes and both mechanical and power shuttle systems.

Although the extra weight and lift capacity of the TL80 will be important to some buyers, the fulsome specification and £3000 to £5000 list price saving make the TN75 a worthy consideration. &#42

Case -IH CX90 versus MX90C

WITH the introduction of the MX-C models to the Maxxum line-up, buyers looking for a 90hp tractor from the Case-IH line have a two-model choice.

Outwardly, the two are very similar – they are about the same size, they both share the same cab (which is a particularly generous design for a tractor in the CX class), and they even share the same engine with side-mounted exhaust installation.

Indeed, these are the only tractors in the Case-IH line-up to feature Perkins engines and both are put together on CNH Globals Doncaster plant assembly line.

The main differences lie in performance potential with heavier, more demanding implements. Because while both tractors deliver 90hp at 2200rpm from their 4 litre, four-cylinder turbo Perkins 1000-series engines, the MX-C has a beefier back-end, multi-speed powershift transmission and more sophisticated hydraulics. There is also a more generous – 196 litre versus 155 litre – fuel tank to give longer working periods before fill-ups.

In the transmission department, both tractors offer much the same in terms of speeds, as there are 16 forward ratios in each case. Although when the optional creep box is added, the more expensive model can deploy 32 x 24 speeds in all, against the CXs 24 x 12.

But while the CX90 makes do with a conventional 16 x 8 speed transmission – derived from an 8 x 4 gearbox with thumb switch operated splitter – the MX90C gets a four-speed powershift on the end of a four-speed gearbox, and the advantage of clutchless up and down shifts under full load.

Moreover, there is the luxury of a power shuttle in place of the CX90s synchromesh forward/-reverse selector.

The CX90s hydraulics system is a generous one for its class given the standardisation on electronic control for fine adjustment and responses, as well as implement damping in transport. But it is comprehensively out-paced by the MC90Cs more generous system.

Variable output means power and general wear and tear are saved when hydraulic oil is not in demand, and 50% more oil flow – 95 litre/min – is available at the remote valves when it is. Lift capacity is a substantial 1280kg up on the CX (measured at the ball ends with the lift arms horizontal).

That, in part, is thanks to the fact that the MX90C is a heavier tractor by some 1560kg. A wheelbase that is only a few millimetres up on the CX provides no improvement in fore/aft stability, but does at least maintain good manoeuvrability – the turning radius of both tractors is practically the same at 4.48m.

Other dimensions are also pretty much the same – the larger diameter standard tyres of the MX-C make only a slight difference – other than when the Low Profile cab is specified for the CX90, which shaves some 70mm off the overall height. With this cab option, buyers also lose the "DL" cabs air suspension seat.n