Turbo diesel – Its dawn.

Turbo diesel cars (and bakkies) tend to have not as good a reputation as their petrol peers. Until the 2000s, diesel engines were still sooty and noisy, so consumers saw them as having an agricultural reputation. In the South Africa automotive market, diesel passenger cars were not a common sight. It was in 1999, with the introduction of the Golf 4, 1.9 TDI, that things started to change. The Golf brought turbo-diesel technology to South African car lovers in the form of an affordable “people’s car”. Then something started to happen. All of a sudden diesel technology became very popular in our country. The focus of mechanical engineers and automakers the world over fell on the South African market.

Turbo Diesel and South African conditions

Other diesel vehicles followed suit, and soon the modern, powerful, and much more refined turbo-diesel cars were commonplace. Then failures started to creep in, and a very popular South African motoring magazine kicked the hornet’s nest.  They published an article on turbo-diesel technology, questioning the reliability of the turbo diesel. The point was, many of the engines designed by the mainstream manufacturers were reliable in their home countries. There were indeed some marginal early designs prone to failing prematurely. The main problem was soon identified. Turbo diesel failures were particular to South African conditions.

Engines at altitudes between 1350 and 1800 meter above sea level, lose much of their power. They can lose between 15 and 20% of their power due to the lower atmospheric pressure. Turbocharged engines boost induction and their loss is far lower. Turbochargers must run at higher turbine speeds in thinner air to produce the same level of boost. Unfortunately, many earlier designs did not sufficiently allow for this. Consequently, several failures were due to prolonging over speeding of turbochargers. South Africans are also notoriously heavy with the foot when it comes to driving. It is bad news if you punish a turbo on a hot day, at high altitudes, for extended periods. Under these circumstances, that turbo diesel engine may just reach its design limits and fail.

Punishing the Turbo

For a long time, turbo diesel vehicles were comparatively rare in the country. When they arrived, South Africans applied their normal foot-on-the-floor driving technique to cars with these engines. However, to get the best reliability out of your turbo diesel engine, you have to adapt your driving style. South Africans tend to be unmindful to this. They are used to robust, large-displacement, naturally aspirated petrol engines. One good thing came from this. The South African lesson had an improvement in the reliability of turbo diesel engines worldwide

Remember that the speed at which the turbocharger spins is not at all proportionate to the engine speed. When the turbocharger reaches its boost threshold, the turbine can be spinning at 150 000 rpm or more. It can deliver full boost pressure, even if your engine is spinning at just 2000 rpm. It is therefore critical to use low revs. It’s equally important to be light on the accelerator while the engine is cold. In doing so, you can avoid spooling up the turbo. The turbocharger is lubricated by oil and can glow orange when worked hard. You cannot just switch off a searing hot turbocharger. If you do so, it may bring on early failure due to overheating and carbonising of the lubricating oil. Drive calmly for the last stretch of your journey. Allow your turbocharger to cool down by idling it for a few minutes.

If you want to read more about turbochargers and reliability, and want to find out what kills a turbo, then click here.

The Unichip

Because turbo-diesel engines are so easy to tune for more power, it is also easy to overstress them. When we fit a Unichip, we measure many parameters. The Unichip optimise your car’s engine safely. It extracts the unused power while keeping a hawk’s eye on the engine and exhaust gas temperatures. In doing so, it maintains your turbo diesel engine’s reliability. Practice responsible turbo care. Become part of the Unichip family and buy your Unichip today. Click here to contact us.