Cold-start driving
I would like your advice about correspondence between myself and the Ssangyong Motor Company regarding my Tivoli. I do not expect you to comment directly on our dispute but merely to offer your opinion regarding the typical performance characteristics of modern, petrol-engined, catalytic converter-equipped, automatic transmission vehicles.
According to Ssangyong, it is a normal characteristic of these vehicles to routinely ‘hang’ in first gear from a cold engine start for the first few hundred yards – and, on at least two occasions, for almost quarter-of-a-mile – to allow the catalytic converter to quickly attain the operating temperature required to comply with emission regulations. They say this happens across a range of similar vehicles produced by other vehicle manufacturers. Neil Pitcher
The modern automatic gearbox is a very complex unit and uses information derived from the engine ECU and sensors, as well as the information from its own ECU unit and sensors. If a problem occurs, it will in most cases illuminate the warning light for either the engine or gearbox system. With such an integrated control system, it is true that the gearchange is controlled to minimise the warm-up time of both the engine and catalyst to the greatest effect. One of the results of this is that the gearchange is delayed.
It is difficult to comment on your particular vehicle without examining it, but one of the factors to consider is the speed at which the vehicle is travelling before the change takes place. If you are restricted to minor roads for the first quarter-mile, it is likely the gearchange would be delayed to this extent. On the other hand, if you are moving off and travelling onto a dual carriageway, it would be expected for the gearbox to change up through the gears a little more quickly. The gearchange can also be affected by your driving style, and releasing the accelerator slightly can often induce the gear selection earlier.
You do not mention if this is a new vehicle or one that has been used for some time. If the vehicle is not new, it would be advisable to check the condition of the temperature sensors, to ensure the correct data is being transmitted to the control units.