Start/Stop system

Am I alone in switching this annoying system off at the start of every trip?
It's not fitted to my old van, but it is on my relatively new automatic car.
Both myself and my wife find it disconcerting to have the engine switch off by itself.
I'm wondering if there's any way to disable this function permanently to save having to remember to flick the switch.
Al.

No you’re not alone. It’s fitted to our van and is a pain.

The reason for stop/start is to cut emissions I believe so perhaps permanently disabling it might be an MOT failure point. Just guessing!

I don’t find it a pain, as it almost never does anything in mine for some reason. I know it’s not somehow disabled, because it has worked on a couple of journeys. Out of dozens.

I have it on my car (2010)and I have it switched off. It rarely worked anyway. Apparently it needs something like 27 criteria to be active to work, such as it has to be above a certain temperature, has to have travelled at least half mile at average of so many miles per hour, plus battery must be above certain voltage. I had it fixed under warranty a few years ago as it had stopped working due to bad earth apparently. Stopped working again couple years ago and hasn't worked since. Passed MOT with it turned off.
I never liked it when it did work, always worried it wouldn't start again at traffic lights.

I've found it doesn't work if the air con is on, which is why it's not operated during the recent hot spell.
I'm sure the potential cut in emissions must be outweighed by having to have a much bigger battery.
Al.

Had it on our Alhambra and once it passed all its parameters as mentioned above never really had an issue with it. However ours was an auto and I think that made it more viable as you couldn't "catch it out" by trying to pull away before the engine was ready.

The current car has a somewhat bigger battery to cope with stop start

I believe that the general rule is that the stop/start function is an integral part of the vehicle's emissions rating, as used in the calculation of vehicle tax. So although the driver can disable it as a specific action for each journey, you are not supposed to be able to turn it off for good - as it would not then be able to achieve its rating.

But there are ways to fool the system. On VW T5's and T6's it's possible (I believe) to change the coding of the ECU so that two of the temperature thresholds for activity are the same (they are supposed to represent a max and min temp) and so there is no circumstance under which it will operate.

But... why bother? In the overall scheme of things, it's not exactly a disaster that the engine stops when you know the lights are just about to turn green...

From the Government web site:

Under the Road Vehicles (Construction and Use) Regulations (Regulations 61(7) and 61A(3)) and the Road Traffic Act 1988 (Section 42) it is an offence to use on a road a vehicle which has been modified in such a way that it no longer complies with the air pollutant emissions standards it was designed to meet.

The potential penalties are £1,000 for a car and £2,500 for a van, lorry or bus.

Under the Road Traffic Act 1988 (Section 75) it is an offence to alter a vehicle in such a way that the use of the vehicle on a road would be unlawful. A person altering the vehicle (if they knew or believed that the vehicle would be used on the road) could be found guilty of an offence under the Act.


As far as the MoT tester failing it the test itself has a very detailed and specific script of what to test and how. There are very few aspects where he can use his judgement. Once the test includes a section to verify a stop start system is active (if fitted) then he can fail it.

Take for example tyres. There are defined faults where he can fail a tyre but the overall condition is not one of them and this includes deterioration. That requires a detailed knowledge of tyres, their condition and deterioration stages which they don't have. So the law does not allow him to fail a tyre just because of its age. There was some talk of age limits of 10 years coming in but that will apply to specific wheels of HGVs and a few special vehicle classes. Even the NDTA ( the trade body) only recommends inspection and treating spares over 10 years old as "get you home" type (the skinny spare)