Hired plant: the short answer
If you are a plant hirer renting machinery from a hire company on a short-term hire contract, remapping the hired machine without the hire company's consent is a breach of the hire contract. Virtually all hire agreements include a clause prohibiting modifications to the hired plant. An ECU remap is a modification.
Beyond the contractual issue, if the remap is discovered — by a hire company technician connecting diagnostic equipment at a service, or by the ECU calibration reference showing a non-factory map — the hirer may be liable for the cost of returning the machine to factory calibration and any associated warranty implications.
The practical risk is low in many cases — hire companies do not routinely check for remap activity — but the contractual risk is real. We advise against remapping hired plant without the hire company's knowledge and consent.
The alternative: buy-out and remap
If you have a long-term hire or rent-to-buy arrangement for a specific machine, and remapping would provide significant fuel savings and productivity gains, there is a case for discussing the modification with the hire company.
Some hire companies will allow modifications with consent, particularly for long-term rent-to-buy arrangements. Some will not. Some will facilitate the remap themselves as part of fleet management.
If you are considering purchasing a specific machine at the end of a hire or lease period, remapping after purchase is the clean approach.
Leased plant: a different position
Plant leased under a finance lease or operating lease is in a slightly different position from short-term hired plant. Finance lease agreements — where the lessee has effective ownership and bears the risk of the asset — may be more accommodating of modifications, depending on the specific lease terms.
Operating lease agreements — where the lessor retains more of the ownership characteristics and the plant is returned at the end of the term — are typically more restrictive, similar to hire contracts.
Check the specific lease agreement for modification clauses before proceeding. If in doubt, seek written consent from the lessor before any remap.
For plant hire companies: remapping your own fleet
Plant hire companies remapping their own fleet — machines they own outright — have none of the contractual complications above. Fleet remapping for plant hire companies is one of the most cost-effective applications of plant remapping.
Hire companies do not typically pay for the fuel used by machines on hire — the hirer pays. But hire companies benefit significantly from improved machine performance (which drives repeat hire and higher productivity for their customers) and from reduced Adblue and DPF downtime, which reduces the cost of emergency callouts and the number of machines off-fleet.
We work with plant hire companies on fleet remapping programmes. Contact us with your fleet list for a fleet pricing discussion.
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Common Questions
Can the hire company tell if a hired machine has been remapped?
Yes — a hire company technician with the appropriate diagnostic equipment can read the ECU and see that the calibration has been changed from the factory map. Whether they check for this routinely depends on the hire company.
What happens if I remap a hired machine and the hire company finds out?
The hire company may charge for returning the machine to factory calibration, and you may be in breach of the hire contract. The severity of the consequences depends on the hire company and the specific contract terms.
Can a plant hire company remap the machines it owns and hires out?
Yes — if the hire company owns the machines outright, remapping its own fleet is entirely within its rights. We work with plant hire companies on fleet remapping programmes.
What if I'm on a rent-to-buy agreement?
Check the specific agreement. Some rent-to-buy agreements treat the lessee more like an owner from the start; others retain modification restrictions until the final purchase. Written consent from the finance provider before any remap is the safe approach.
Would a hire company ever allow a hirer to remap a machine?
Some would, particularly for long-term hirers. It is worth asking — the worst answer is no, and some hire companies are open to it if the machine is returned to factory spec at the end of the hire period (which a remap can be, as the original calibration is backed up before any remap).