Photo: screenshot from Youtube/edited by autoevolution
As you may have heard, Toyota just revealed two new thermal efficient gasoline engines. They don’t exceed a capacity bigger than 1.3-liters but the automaker said they are 10 percent more fuel efficient and almost as fuel efficient as hybrid powertrains. But how did the engineers made this possible?
First of all, Toyota wanted its engineers to work and communicate in harmony, so the company raised a whole new building called The Unit Center. Here, engineers were assigned with one single task - improve their engines’ thermal efficiency.
If you’re new to mechanics, thermal efficiency means how efficient an engine can use the gasoline its being fed with to power the car. Each drop of gasoline has contains a certain amount of energy it can set free by burning in an engine cylinder.
However, not all the energy goes to your wheels. Most of it escapes through heat and the engine’s internal parts that come in contact and create friction. But this there are just the basic energy eaters in an engine; how the gasoline is mixed with air and how fast it will burn also determines how efficient efficiently its being used.
The next step in designing a more thermal efficient engine at Toyota’s HQ was the burning process itself. Engineers wanted the fuel to better mix with air, better fill the cylinder and thus burn faster and completer. This has been achieved by a reshaped intake which creates a a tumble flow.
Next, they achieved a higher compression thanks to enhanced control of the combustion chamber temperature to prevent knocking. They also used the Atkinson cycle paired with the standard electronic VVT and refined EGR.
Last but not least, engineers minimized internal friction through a modified piston skirt surface, plastic-coated bearings, new structure water jacket spacer, reduced capacity oil pump and an auxiliary belt with reduced bending loss.
Overall, the new Toyota 1.3-liter gasoline engine achieved a thermal efficiency of 38 percent, which at the moment is the highest in the industry, while the 1-liter unit is just one percent bellow. Further pairing these new units with start-stop technology will reduce fuel consumption by around 15 percent.
Google News