Should I buy a petrol chainsaw?
By Adelaide Gray
Top-notch petrol chainsaws will cut through wood quickly and cleanly, but are they too noisy and powerful for your needs?
Is a petrol chainsaw right for me?
If you have a lot of logs to cut or heavy pruning to tackle in the garden, a petrol chainsaw is a good choice; it will cut through large logs faster than any other machine and you can use it anywhere without the hassle of a trailing power cable.
It will need regular maintenance including:
- Servicing the engine
- Keeping the fuel tank topped up
- Sharpening the cutting teeth
- Keeping the chain at the correct tension
Petrol chainsaws are also heavy, so it’s worth testing one out before you buy to check whether it’s a tool you could use comfortably. Consider how you would use a chainsaw for different jobs: pruning branches would involve making single cuts with rests in-between; chopping logs would be a series of vertical cuts in a continual motion.
There’s no escaping the fact that petrol chainsaws are noisy. Some are noisier than others, but all are likely to irritate the neighbours if you use them constantly. They also give off powerful petrol fumes.
Pros: Powerful, portable, great for chopping logs
Cons: High maintenance, noisy, overpowering emissions, expensive
Which petrol chainsaw should I buy?
Petrol chainsaws come in different sizes and power capacities depending on the sort of work they’re designed to do, from pruning the branches of a shrub to felling large trunks.
Generally, there are three categories: domestic use, heavy use and professional use. Most of the petrol chainsaws you’ll find in DIY stores and garden centres will be designed for domestic use and have a guide bar of 40cm or less. These are the best choice for cutting jobs around the garden.
Choosing a chainsaw isn't just about cutting; you want a machine that's easy to use, manoeuvre and maintain.
Husqvarna and Stihl are two very well-known chainsaw brands. Find out how what Which? members think of them in our Best chainsaw brands guide.
How does a petrol chainsaw work?
A petrol engine drives a metal chain, with lots of cutting ‘teeth’, at high speed around an oblong-shaped guide bar. As the spinning chain makes contact with a log or tree trunk, its teeth are dragged along the surface, cutting the wood. The circular motion of the chain keeps the teeth in contact with the wood, so the saw keeps cutting until it has sliced all the way through or the power is stopped.
Most petrol chainsaws have two-stroke engines, which are similar to those used in mopeds or outboard boat engines. They normally sound similar, too – just think of the noise a moped makes to get an idea of how loud these machines are.
It’s worth bearing in mind that a petrol chainsaw’s engine will require regular servicing to keep it in good working order.
Oil and fuel for petrol chainsaws
Petrol chainsaws need a certain type of fuel, which is a specific mix of petrol and engine oil. Most petrol chainsaws run on a 50:1 petrol-to-oil ratio, but check the user manual for the exact ratio your chainsaw needs.
As well as the right oil-fuel mix, petrol chainsaws need lubricating oil to ensure the chain runs smoothly and doesn’t snag. Look for a chainsaw with an integrated oil chamber that supplies this oil automatically, as this will save you time and hassle; most models come with these as standard, but it’s worth checking before you buy.
If you don’t use a petrol chainsaw regularly you must drain it of fuel and oil between uses.