In answer to a direct question above about my view of stop start systems:
They are a triumph of marketing (driven by market forces) over engineering. And it's "our own" faults
Here in the UK, despite the fact that VED is a drop in the ocean compared to the total cost of running a car, the level of VED any particular car attracts has a massively disproportionate effect on percieved value in the market place and hence on sales. people will moan like Bill about VED levels, yet never a murmour about depreciation!
Now, the Government knows this. It also desires to reduce pollution levels caused by burning fuel. So it decides to manipulate market forces by setting a VED regime that cajoles consumers into smaller more efficient cars, which in turn cajoles manufacturers to make more efficient cars. It uses CO2 as the measure to provide a percieved link between pollution and the size of your car. It's phsycological warfare - trying to shame you into a smaller engined car.
The automotive industry then sets about creating Engineering solutions to this new marketing need. Many of the solutions are excellent: smaller capacity turbo engines; improved aerodynamics; reduced vehicle weight; more efficient engines; fuel cut off on overrun and so on.
At least one solution isn't so good (well, further down the ownership line that is); automated manual dual clutch gearboxes.
However, there is still a problem. In congestion, no matter how small and efficient ythe engine, it still burns fuel whilst idling and going nowhere, increasing local pollution levels. So the mandated test regime for determining CO2 output includes a simulated drive cycle which in turn includes a period of idling. There is nothing in the test rules that says the engine MUST remain running during the idling portion of the test and so some bright spark somewhere spots that the total test CO2 output can be cut by stopping the engine during this portion of the test.
Now this doesn't achieve much in reality, maybe 5 or 10 grams overall, but this is enough in some cases to drop a car into the next VED band down. So, voila, a marketing advantage is born and suddenly cars have stop start fitted. Boom!
This brings it's own challenge. It stresses the cars starting system. So it gets beef up. By just enough to keep warranty at bay whilst not eroding the marketing advantage by adding too much cost or weight.
The cars showroom appeal is improved by it's "percieved" economy and reduced VED.
Boom! Hoisted by our own petard! Our en-mass gullibility exploited to the max!
Stop/start is a disaster for the longevity of engines and systems. It stresses so many components, including the driver.
Edited by Cyd on 24/11/2017 at 13:32
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