This can only afford a stuccoon: just before the end of the current compact car generation, volkswagen donated the golf tgi, the skoda octavia g-tec, the audi a3 and the seat leon a new natural gas powertrain with slightly intolered tank. In view of the previous cng stucco numbers, this is a remarkable step – at least at first sight. Because of course, this combination will conceive in probably absolutely identical form in the successors, with which in the year of annual period is expected at all four. We wanted to know how the new powertrain suggests and whether it is worth buying him in a run-up model. For this we have a seat leon 1.5 tgi for a test brought to the editorial.
Technically, the update is shortly before the goal of this generation superficial is not particularly spectacular. The well-known 1.5-liter four-cylinder, which has existed as a gasoline with 130 and 150 hp in various models for some time, was made fit for operation with natural gas. He benefits from a further development against the gasoline in the area of the cylinder head. This was redesigned in detail, with the power optimization in the foreground. He is only installed in the cng engine for the time being, later the gasoline.
Since methane burns not only worse but also heir, volkswagen had to change some components. Valves whose seat rings and guides was prepared with a nitration on the high temperatures. The inlet and outlet cams were completed to the rear minimum flat. This makes the valves slower, which should reduce the wear. Below in the crank mechanism, the connecting rod bearings were changed – even here with the same goal.
More tension and cooler
The turf coils supply a high voltage in the top than in the gasoline engine to ensure a safe ignition of the mixture. But the big change was made in the feed of the gas. This is not blown directly into the combustion chamber, but in the suction tube, so in front of the inlet valves. Volkswagen uses, like the 130-horsepower petrol engine, on a vtg loader and the miller burning process, where the intake valve will take as a ugli. This lowers the highest temperature during the compression. Thus, volkswagen can drive with gasoline a high compression of 12.5: 1 without getting in the area of knocking. In addition, the high knock resistance of methane. The gas prere regulator is conceptually from the vw polo tgi (test) and was used for use in the 1.5 tgi only slightly changed.
Unfortunately, volkswagen has not been able to run through to interpret the machine monovalent. For emergency, operation is still provided with gasoline, which in turn means compromises in gas operation. The advantages that a monovalent gas engine could offer will not be completely spotted. Nevertheless, at least in some areas, it has succeeded in driving a peak print of 130 bar. In operation with gasoline, the engine was so violently ringing that he was quiet within a short time forever.
At the previous 1.4-liter natural gas engine, the new machine sets up to power: 130 instead of 110 hp it is now. The maximum torque of 200 nm remained the same, but is now a sudden and on. Unchanged in the day-to-day handling but a lane weakness below 1500 / min. Only druber is ahead, really live in the booth is only from 2000 / min. The nominally equal powered 130-hp gasoline engine is minimal flicker in the default sprint, but overall the leon with natural gas propulsion seems far more than just enough. The opel astra cng (test) he fits a lot further behind himself when the factories suspect.