These chips are also sold for campervans and motorhomes. One school of thought says that they work: a little more torque for the same fuel consumption, or the same torque for a little less fuel consumption, depending upon your choice of chip.
The other school of thought says that the gain is pretty small, bearing in mind the bulk and aerodynamics of a typical motorhome, and there is a bit of a risk to the innards of the engine. Somewhere along the line you must be either reducing the amount of fuel, with possible consequences for running the engine lean, or making the engine work harder if you are "forcing" it to produce more power.
I am not aware of lots of owners claiming that a chip actually damaged their engine, so I guess chips must be basically OK, but I think the benefits, as far as campervans are concerned, may be described as pretty marginal. In the confines of a smaller, lighter vehicle, the results may be more noticeable.....
I have no commercial interest in anything to do with any of these chips, and have never used one on any of my vehicles......