Having heard there was new engine technology, we expected something good. But nothing could have prepared us for the improvements brought about by using X-TORQ.
The 455 Rancher is a powerful, tough saw aimed at landowners needing to do a professional job. It is powered by a 55.5cc engine and is an all-round workhorse but, because of the targeted user group, it is also easy to use.
This one has a primer bulb. For tree surgeons that may seem as though it is going back in time, but it is well recessed and protected, and it does make starting the saw easier for those who do not use chainsaws every day of their working lives.
Construction of the 455 Rancher also reflects the use this saw is probably going to see. As with the professional Husky machines, the Rancher has a precision-forged, three-piece crankshaft for durability.
The box-shaped crankcase is made of composite, reinforced with aluminium so it is strong but lightweight. There are no protruding parts and the smooth underside plus the well-protected controls should maximise the life of this saw — even in the clumsiest of hands.
The Rancher has heavy-duty, fuel-resistant steel springs in the LowVib system. The springs should also be better able than rubber elements to withstand temperature variation and UV light. The air filter sits under a snap-on cover so it is easily accessed for cleaning or replacement.
Aimed at skilled professionals who need tools to keep them at the top of their trade, the Husqvarna 575XP is a bigger, 73.5cc machine. It has been designed for long operating periods and features air injection to effectively clean the intake air for a smoother-running machine with reduced wear and extended time between air filter cleaning. In fact, Husqvarna reckons that the new system increases the period between cleaning by up to 20 times.
This model also has an optimised cooling system and angled cooling fans to provide 35 per cent higher air flow around the engine and reduce the risk of debris accumulation on the cylinder. The snap-lock cylinder cover gives quick and easy access to the spark plug and air filter. And the easy-access side-mounted chain tensioner adds to this saw’s user friendliness.
But what of the X-TORQ?
Here, we need an explanation of the X-TORQ feature. During the intake phase, air and fuel is mixed in the carburettor. The air/fuel mix is then drawn into the crankcase. That all makes sense so far. Through the second passage, pure air is drawn through the top portion of the transfer ports.
After combustion, as the piston travels down towards the bottom, first the exhaust port is opened and then the transfer ports open to allow the pure air into the cylinder from the crankcase. This pure air pushes the exhaust gas to the muffler, preventing unburned fuel from reaching the muffler. Once the pure air has been pushed into the cylinder, the air/fuel mixture enters the cylinder through the transfer ports.
The reduced amount of unburned fuel in the exhaust fumes means that emissions are drastically reduced and the unit’s fuel economy is enhanced. Put more simply — this is a clean, lean, powerful machine.
X-TORQ engines are designed to deliver much higher torque (that’s low-end power) than the standard two-stroke engines, over a wider rpm range. This should give the user maximum cutting power. Our testers confirm that it does.
Husqvarna claims that the X-TORQ engine consumes approximately 20 per cent less fuel than standard two-stroke engines. Incidentally, the 575XP has newly designed fuel and oil caps that are easy to unscrew without using tools. The new engine technology also meets and exceeds emission standards for 2010 and beyond.
Both saws impress our testers. I can’t find fault with them, says one tester. There’s plenty of power and speed on cutting, the handles are good for gripping, the vibration is nothing and the controls are just where you need them and easy to work. And the 575XP starts well — just a little pull and it’s away.