New Sasol GTC cars set for thrills

The iconic Grand Prix Circuit will present a new challenge to the GTC drivers as they tackle the country’s fastest racetrack on June 16.

Suzuki’s new Swift hatch and sedan in SA

Suzuki kicks off its new model assault with an all new Swift hatchback and standalone sedan called the Dzire.

Reducing road rage with stop/start

2011-03-04 06:25

Lance Branquinho

SWITCHED ON?: Is new start/stop engine technology a godsend for urban commuters or a possible long-term maintenance nightmare?

During the past year I drove two cars aimed at rather different segments of the market, both of which happened to share an engineering feature.

Alfa Romeo’s MiTo and VW’s new Touareg were two of the first cars in their respective market segments to feature stop/go technology as part of a suite of engineering features intended to reduce fuel-consumption by improving efficiency.

I intensely dislike silly engineering, especially when the benefit is barely traceable either tangibly (on the road) or statistically (as part of the cost-of-ownership experience). Let's just say stop/start engine cut-out has always appeared to be a bit much of muchness to me.


My first experience with it was rolling to a stop a few traffic lights homeward bound from the office one night and having the MiTo suddenly "stall" on me. I fiddled to co-ordinate a restart, then swiftly remembered the disarming little Alfa’s engine featured stop/start technology.

After a few days with the system it graduated to being a calming part of navigating hectic city traffic.

When traffic opened up the MiTo’s ability to generate 125 rather keen kiloWatts of performance was greatly engaging. When progress slowed – or stopped entirely – it was a cathartic experience to sit and let the infotainment system do its work with the tachometer needle at zero.

Whereas the MiTo’s stop/start is geared to operate with a manual transmission, the Touareg’s BlueMotion technology runs off an eight-speed auto. Like the MiTo, as soon as the engine reaches a desired operating temperature, the Touareg’s three-litre turbodiesel V6 stops when the car stops. Releasing the brakes instantly restarts the V6.

The question remains: is it a gimmick? To my mind: No. It can mean a fuel consumption saving of five to 10% in severely trafficked areas (such as most of Gauteng).

What appealed most to me was not the reduced fuel consumption but the system’s seamlessness – I was never near stalling the MiTo due to tardy re-ignition when depressing the clutch and engaging first gear.

TOUGH ENOUGH: An experimental integrated started generator (ISG) set-up, developed for Ford by French company Valeo. Engineers say these ISG units have a high tolerance for the multiple starts required each day from a start/stop system…


On a subliminal level, I believe stop/start technology calms drivers in stressful traffic.

It removes all perceptions of waste that occasionally inflame attitudes in traffic - when fuel is wasted by idling, well, idly. When the engine is off, you feel a (slight) sense of contentment despite being stuck in traffic, knowing that you're not wasting fuel as well as time.

Is stop/start technology a pure emissions-curbing measure only? Not quite, to my mind it is neat engineering, majoring in efficient design - though there is a question about increased starter-motor wear...

I found myself having to strain logic with regards to the Touareg’s BlueMotion stop/start system’s durability. Diesel engines run high compression ratios and as such also have heavier, tougher internals to cope. Therefore, tradisionally, you required a substantial starter motor to get the compression cycle going - not something that takes well to the wear of frequent starts.

Despite the considerable advances in diesel engine design through the past decade (especially glow-plug warm-up cycles and direct injection efficiency), I was initially sceptical about the durability of a starter motor running the stop/start system on a large turbodiesel such as the Touareg's V6.


In practice the system was outstandingly calibrated, adjusting to thermodynamic factors and only running when ambient and internal temperatures were optimal. Such systems have been working for some time now in Europe, where urban traffic is epic in cities such as London, Rome, Paris and Frankfurt. Their durability has been proved.

There is, however, a caveat to operating stop/start in a hot climate such as South Africa. Luxury vehicles, like the Touareg, prioritise cabin comfort (keeping the aircon running on a hot day) above ultimate efficiency. As a result, you’ll probably see the system intervene far less (if at all) on a sweltering Highveld summer’s day.

DIALLING IT DOWN: With more manufacturers set to introduce stop/start tech in South African in 2011 expect to see more tachos kipping in traffic…

The issue at hand is not only one of saving fuel and reducing emissions. Stop/start technology could have another benefit too, pertaining to large capacity performance cars.

Although the era of the large-capacity, unblown internal-combustion engines is nearing its end, stop/start could be beneficial for them, too.

There's nothing worse than babysitting a large capacity V8 in crawling traffic on a scorching day and watching the coolant temperature gauge rise steadily due to a lack of cooling airflow.

If you can shut it down when not moving, then why not?

As anybody who's been silly enough to remove a car’s thermostat (me) or been stuck in traffic with an overheating car (me, again, and yes - I employ the old "maximum-heater-setting" ventilation control trick to divert some heat from the engine bay into the cabin) will attest, stop/start would be a godsend.

All things considered, is stop/start technology a negligible fuel-saving gimmick? It very much depends on how much city driving you do. Navigating Gauteng’s maddening traffic will show it to have an undeniable benefit.

I liked the technology primarily for its ability to erase the sense of frustration caused by idling away fuel (and running up friction wear) while your car does exactly what it was never designed to do: remain motionless, wedged between two other motionless cars, in traffic…

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