His first flaw was where he stated "Whatever they’re called and whatever method is used, they all do the same thing – dump more fuel into the engine to generate more power." That's not exactly true: chips like Unichip adjust injection timing, Steinbauer adjusts injector duration, ChipMyDiesel reduces duration while increasing pressure and ChipIt plays with the turbo vanes ... there are lots of variations.
He does have a lot of valid points. Some of his wear-and-tear notions are skewed a little, because the whole idea of "tensile strength" and "breaking strain" (referring to testing of metal components) is based on the point at which you can cause those components to fail (ask any metallurgist or mechanical engineer). You can chip an engine to the point where it is going to fail: stick a NoLimits chip in on max and take the car for a run up Mt Ousley with 3T behind you and your foot all the way to the floor. Bet you don't see the top of the hill! EGTs will rise so much it'll kill itself.
Fundamentally though, the guy's right. Our engines are designed to deliver a certain amount of power using a certain amount of fuel and pumping out a certain level of emissions. Based on the designed levels, our engines can expect to have a certain lifespan. Push the boundaries and you risk reducing that lifespan. Note that I didn't say WILL reduce it - it's a RISK.
That's because some people buy chips and install them and use them for economy, rather than the increased power that is available.
One other point: if you have an auto, and you're chipping it with the intention of lowering your torque and HP peaks, your success will be limited by what's known as the "Stall point" of the torque converter. It's because of how a TC works. In the TC, there are plates that slide in close proximity to each other with nothing but oil between them. At a certain RPM, the oil grips the plates well enough to "connect" the plates, similar to a clutch. The point where the grip is enough to kill the engine when the wheels are stopped (foot on the brake, vehicle in Drive and using the accelerator) in our Navaras is around 2700-3100rpm. This is the point where the driven shaft has no choice but to turn over (like dropping the clutch).
If you bring the peak torque point too low, it will be inside the larger slip zone (more than 500rpm below stall point) and you'll basically waste engine revs (= wasting fuel).
You can get a lower stall speed TC from Wholesale Automatics in Victoria, that brings the stall speed down to around 2400rpm - that's a good unit, but pricey.
