Andrew Koch Crosses the ‘VW Golf’ between Diesel and Petrol…
Just when you thought that you could pigeon hole an engine type depending on whether it was petrol or diesel, think again, because once you read below, it’s more than likely that thought will be turned on its head. Choosing between petrol and a diesel engine for your new VW Golf is not easy. Both offer a lot of benefits. Now VW has made it easy for you, with the new TSI engine that, amazingly, really does offer the best of both the petrol and diesel worlds.
This is no ordinary fast Golf. It sports two ‘chargers’, super and turbo, on a petrol engine that brings the advance of the diesel to a shuddering halt. It’s not often we can get excited about the arrival of a new engine that does so many things so well. But we can do so here.
The concept of twin charging is not new. It was successfully used by Lancia in the 1980s on the Lancia Delta S4 rally car. The idea was also successfully adapted to production road cars by Nissan, in their March compact car, and now by the Volkswagen Group, in their Golf and their Touran model, which isn’t sold in Australia.
The ever increasing challenge for car makers is the struggle to meet ever lower emission targets, while at the same time retaining the performance that customers still demand. One strategy is to combine the benefits that petrol and diesel power plants currently offer in one affordable engine.
What was needed was an engine that is smooth and quiet (as found with petrol power) combined with high torque at low engine speeds for quality of driving, flexibility, responsiveness and fuel economy with low emissions, as found in the latest direct-injection diesels.
Step forward VW’s new TSI technology, as seen on its latest 1.4-litre direct-injection petrol engine twin charged with a supercharger and turbocharger. At its core, TSI uses a 1.4-litre FSI (Fuel Stratified Injection) engine that is then twin charged through a combination of an engine-driven supercharger and an exhaust gas turbocharger.
The belt-driven supercharger operates at lower engine speeds, with the turbocharger coming in as engine speed increases to create a seamless progression from one source of boosted power to the other. In the mid-range at the changeover point, the blown air from the supercharger is diverted into the turbocharger for a short period before the turbocharger takes over completely.
This arrangement provides excellent drivability and performance throughout the range, with high maximum torque but no turbo lag. It combines the particular benefits of both petrol and diesel engines: petrol characteristics are low noise and vibration; diesel qualities are good drivability, high torque from low engine speeds and fuel economy.
The new TSI engine has a capacity of 1.4-litres and outputs 125kW, the same peak power as a conventional 2.3-litre petrol unit but with 20 per cent lower fuel consumption, returning 7.7L / 100kms on the combined cycle. It also produces maximum torque of 240Nm from 1,750 through to 4,500rpm.
TSI prices start at $34,990 for the Golf GT Sport, with the fast-shifting DSG automated transmission costing $37,290
As a price comparison, the Golf with the 2.0-litre FSI engine is priced at $29,990, showing the new TSI engine has a price premium of $4,000.
When you look at the ‘paper’ specification and performance figures for VW’s new 1.4-litre TSI twin charged petrol engine and see it is more powerful, faster, more fuel efficient and less polluting than the relatively-new 2.0-litre FSI direct injection petrol engine, it’s hard to believe what you’re reading can be possible.
But, I can assure you, it most certainly is. At last, a petrol engine which drives like a diesel but is quieter – although not yet quite as frugal with fuel. Turn the ignition key and the new 1.4-litre unit springs into life  no diesel rattle or clatter. Slip it into first gear and accelerate. Change up to second, third, fourth and so on and there is a huge amount of power. And, more importantly, torque  making the car easy to drive at slow speeds in town or in traffic. On the open road, thanks to supercharger and turbocharger power or a mixing of both, the engine is really responsive and strong during acceleration. There are no steps between these boosted stages. It is a petrol unit, but it’s just like driving a diesel.
Australia is learning to like diesel power, and the quality of driving and fuel economy these engines give. What they don’t like is the engine noise. TSI technology really will appeal to the diehards who want to remain petrol car users and I can see TSI converting a few diesel users back to petrol. Perhaps the fuel economy is not yet quite as good as a diesel engine, but it is not too far away.
There is no doubt about it  the fuel economy potential is there. Driving on the highway the actual consumption reading was showing 5.4L / 100kms. But what is most impressive is that such a relatively small engine can give the quality of driving and acceleration only found in much larger petrol engines or with diesel units. TSI technology is a very big step forward. In addition, TSI powered Golfs come with all of the plus points of petrol and diesel engines in one. A slight price premium over FSI models is a very small price to pay. So, Volkswagen, Well done!
