Tips to increase the performance of a flat four-pot tractor

Four-cylinder tractors are a staple for most farms offering the right blend of power and size to cater for a wide range of jobs from daily feeding and bedding tasks, but also equally capable in the field with a drill or fertiliser spreader hooked on the rear.

However, an increasing number of users are finding that new four-cylinder tractors are coming out of the factory with less performance than their predecessors.

Emissions controls and model classification mean that purchasing a 150hp tractor can feel more like a tractor lower down the model range.

Gareth Jones, director at Avon Tuning HD (ATHD), says it’s an increasingly common issue that the network of ATHD remapping engineers are finding.

“We are regularly remapping four-cylinder engines to provide modest power and torque increases to improve tractor performance and match the stated output on the side of the bonnet,” says Gareth.

“This isn’t about adding lots of extra horsepower that the drivetrain can’t handle but safely increasing power delivery and timing to suit operator preferences.”

Manufacturers will build new tractors to operate safely and efficiently in any condition, which means machines might not be running at peak efficiency for certain tasks.

This can lead to operators feeling a new machine is underpowered compared to a previous model. In the case of four-cylinder tractors, this is a common occurrence.

Professional remapping can change how the power is delivered throughout the rev range to enable power delivery when the user requires it and a tractor that is easier to use.

This could mean accessing power and torque at lower rpm to allow the transmission to stay in a certain gear longer, ideally when ploughing or hauling a trailer up hills.

Furthermore, many users of remapped tractors also point to considerable fuel savings as machines can operate at lower rpm whilst delivering performance improvements.

“Fuel savings of between 5% and 10% are achievable in some situations,” says Gareth.

Next model up

Another area that is becoming popular, especially with four-cylinder tractors, is next model up remapping.

Farmers are purchasing a tractor that is one or two models below their requirements in the range and then remapping the ECU to deliver the power similar to their bigger siblings.

Manufacturers will be keen to point out the benefits of individual models, but most will be variations on the same framework, with the ECU adjusted to limit power output as the models get smaller.

By building a top model capable of handling the power and torque, it allows manufacturers to detune outputs to provide more models.

This is one area that professional remapping can really help users make sizeable savings on buying new.

Changing how mid-range power is delivered can benefit haulage work, with lower torque reserves reducing the requirement to rev high in each gear.

It is essential to choose an engineer or network that has done this work before as it could lead to problems without the right research into the model.

“Dairy farms and buildings can be small, so increasing power and moving to a larger frame tractor, or changing from four to six cylinders, isn’t an option for most farmers.

By adding modest gains to smaller models, users can experience improved performance without the high purchasing costs or inflexibility of a bigger model.

Not all model series will be the same though, for instance, small and large frame tractors will have different components, so we have to be certain the machines can handle the increase,” says Gareth.

Further to this research, a health check on the tractors should be carried out before any remaps are added.

This provides engineers with a clear mechanical picture of any underlying issues that may affect the performance and reliability following a remap.

Case study: Four-cylinder remaps increase engine response

Somerset beef and haylage producer George Baker used Avon Tuning HD to remap his brace of New Holland T6.175s.

These new tractors were the four-cylinder replacements for his previous six-cylinder models, with the main reason for changing being the appeal of New Holland’s Dynamic Command Transmission (DCT).

Immediately, George spotted that the new tractors were underpowered compared to the previous models, despite having the same rated horsepower on the bonnet.

He says the plan wasn’t to make the tractors something they weren’t, but to deliver the power they were rated to.

“When the tractors turned up, they were unresponsive and we couldn’t get on with them.

“We immediately called ATHD and the remapping has made a massive difference, it’s completely changed how the machines run and drive.

“Avon’s attention to detail and making sure we were happy gave us confidence in the modification and trust in the software.”

George has subsequently purchased a New Holland T6.180, which has a six-cylinder engine and the same DCT transmission.

This allowed him to compare a remapped four-cylinder against a bigger six-cylinder and he found the former was more than a match and outperformed the six-pot on certain tasks.

“From a drivers’ perspective the four-cylinders are more responsive and driver friendly.

“It’s not about screaming every horsepower out of the engine, but they respond much better with bigger implements on the back, such as our 5m Kuhn HR 5004 R power harrow.”

George continues: “It’s not trying to make a tractor what it isn’t. Drivability from a low-end torque perspective is the biggest change.

“When the tractor isn’t revving hard on loader work, the four-cylinders are much more responsive than the six cylinders.”

Fuel saving

George is keen to point out that while Avon don’t advertise that remapping will save fuel, there are some improvements to fuel use since the tractors received the new maps.

“I believe remapping does save fuel in the long run, especially when a tractor is doing a variety of jobs likes ours, from loader work to cultivations.

“For example, when we are mowing, we aren’t constantly up and down the gears. It’s the same with ploughing, we can drop the revs down as there is more torque available at the lower end of the range, so this is saving fuel.”

One thing George prioritises is reliability and he says the tractors haven’t had any major breakdowns, which shows the maps don’t negatively affect reliability issues.

He says there have been the usual issues with tractors, but nothing that is directly related to the improved performance.

He says that choosing a well-respected company to do the work means he is confident in the outcome.

“I’ve complete trust in the Avon remapping service and the agents carrying out the work.

“It’s quick and efficient, but they also check that my tractors can handle the increases and would advise me as such if they felt there was an issue.

“If you choose a well-respected company, then you’re putting your machines in the hands of the right people,” concludes George.