Originally Posted by husky.com

X-TORQ Engine Technology

Reduces fuel consumption, emissions while maintaining power

Professional outdoor power equipment users are always looking for greater power in smaller packages, but regulations and concerns about environmental impact have complicated this effort for manufacturers. Husqvarna has faced these challenges by creating X-TORQ engine technology, which reduces emissions and fuel consumption while maintaining performance.
Husqvarna has been a pioneer in the effort to produce quality products while addressing emissions issues, as the company was the first manufacturer to introduce outdoor power equipment products with catalytic converters to the U.S. To create X-TORQ technology, researchers spent years testing and evaluating engine performance utilizing cutting-edge methods and materials. As a result, the demands of exhaust emissions regulations are met while the quality and performance that professionals expect from Husqvarna products is maintained.

X-TORQ engines deliver high torque even at low rpms, offering more useable power on demand, so operators can complete projects effectively and efficiently. More productivity with X-TORQ engines means more money in the pockets of professionals and jobs done faster for the consumer.
In addition, X-TORQ innovations offer up to 20 percent lower fuel consumption and up to 60 percent lower exhaust emission levels, resulting in a better working environment.

A conventional two-stroke engine has standard components like the air filter, which cleans the air brought into the carburetor. The carburetor’s main duty is to blend the fuel and air which is necessary for combustion. The crankcase, which houses the crankshaft, becomes the point of entry for the fuel/air mixture. During the engine cycle, fuel and air is brought upwards through the transfer ports into the cylinder where the mixture is compressed by the piston and then ignited. The exhaust then is removed through the muffler. In this process, some of the unburned fuel can escape into the muffler from the transfer port. This unburned fuel is then released into the atmosphere. This is called scavenging loss and is the source of the harmful emissions from traditional two stroke engines.

With new X-TORQ technology, the primary engine components still exist, so the basics would be familiar to any two-stroke technician. The air/fuel mix enters the crankcase just as the traditional two-stroke engine. However, there is a second stream of unmixed air moving through the piston and entering the transfer ports at the upper end. This unmixed air becomes the first element that enters the cylinder. This clean unmixed air then escapes into the atmosphere while pushing the exhaust out with it. This is usually when the unburned fuel would escape in a traditional two-stroke, but since the clean unmixed air reaches the cylinder first, the clean unmixed air is what escapes. This process reduces scavenging loss, resulting in lower emissions and greater fuel economy.

Unlike four-stroke engines with numerous moving parts and constant valve adjustments, this technology does not require special oils to reduce coking or carbon build-up. X-TORQ’s two-cycle technology innovation offers more torque in the cut, less fuel consumed while doing it, and a cleaner environment in the process.
When faced with challenges, Husqvarna will continue to seek out new technologies and to lead the industry in innovation. X-TORQ technology reflects the most recent results of those efforts.