Car Care: Tweak at your peril
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'Chipping' your car may have unwanted side effects, advises Jack Biddle
My ears pricked up when I overheard a group of motor vehicle enthusiasts talking about the benefits of having an engine’s electronic computer control unit “chipped” to improve engine performance. Apparently one owned a turbocharged diesel-powered vehicle that he felt lacked top-end performance.
The vehicle was not long out of its new-vehicle warranty and so free of any distributor warranty restrictions, which the owner felt made it an ideal candidate for performance enhancement.
I wasn’t as convinced and wondered if the risks of this modification had been worked through. The vehicle was basically a mass-produced motor vehicle designed for more day-to-day tasks rather than anything that required top-end performance.
If anything, its initial claim to fame was centred more around price than performance — another reason to raise my eyebrows.
“Chipping” is a fancy word for tampering with a manufacturer’s pre-set programme in the computer.
Research and development teams ensure mechanical components are not overly stressed and not on the limit of their capabilities for even the shortest time.
Priority is also placed on smooth performance in urban and highway driving conditions while meeting consumer expectation of reasonably good fuel consumption.
The other pressure on manufacturers is to meet independent, strict and non-negotiable global tailpipe emission standards for a particular market.
Manufacturers spend millions of R&D dollars to deliver the best all-round package in the hope a vehicle will deliver long-term reliability. The key word is compromise however: getting that balance just right.
The risk owners take when they step outside the standard factory computer settings is the potential benefits in one area of performance being at the detriment of the opposite end of the performance scale.
Endeavouring to increase top-end power output, for example, can not only place unwanted stress on the engine, transmission and components such as turbochargers, it is highly likely to increase overall fuel consumption. Owners may also experience rough running when that top-end power is not required.
With the introduction of electronics in mass-produced engines in recent times, the opportunity has been taken to change an engine’s characteristics under certain conditions.
Sensors are constantly monitoring conditions such as speed, throttle position, engine revs and temperature as well as gear selection. Subtle changes are continuously being made to ensure the best overall performance is achieved.
There’s no doubt top-end performance can be enhanced by tweaking the electronic computer unit and those who specialise in carrying out these modifications are very clever. But they are often focused on one end of the performance ladder and I’m sure they would be the first to acknowledge there may be downsides.
And owners shouldn’t expect the same mechanical warranties when such modifications are carried out.The manufacturer usually knows best what their engines are capable of and how far modifications should or can go.