Stihl
MS 171
Test score
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Some chainsaws are packed with high-spec features, but still don't start well and struggle to get through hard wood. Others are basic, but start first time, every time and cut through even the thickest logs easily.
The only way to tell if a chainsaw is any good is to cut through some wood with it, which is why Which? does exactly that in our independent lab tests. Our recommended Best Buys take the risk out of choosing a new chainsaw.
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Sign up nowIn this video you'll find out what it takes for a chainsaw to earn our coveted Which? Best Buy recommendation, and how a Best Buy could make a real difference to your heavy pruning jobs.
To find out how well each chainsaw cuts our independent experts make a series of cuts with each machine through logs of different sizes, from a small, 5cm-diameter branch up to a 30cm-diameter log. They record the time it takes to make 10 cuts and rate how cleanly the cuts are left.
To really put these chainsaws through their paces, we run them through a hard wood log, such as chestnut or oak, and a railway sleeper, timing how long it takes and rating how cleanly they cut. The best chainsaws will power through these obstacles with ease.
See the best chainsaw brands.
Our tests start long before we switch the chainsaw on. We assess how easy each machine is to put together and we review the quality of the instructions.
The best chainsaws are simple to hold and use for a range of cutting jobs, so we conduct a total of 21 different tests to see how easy it is to use each chainsaw.
And how well each chainsaw can be manoeuvred among branches, to rate how easy it is to use for heavy pruning.
There’s no escaping the fact that chainsaws are noisy machines but, while some are tolerable, others are extremely loud and may annoy the neighbours. So we rate each chainsaw on how noisy it is and how irritating this is likely to be to others.
Avoid accidents and injuries by using our chainsaw safety checklist.
Chainsaws require a fair amount of regular maintenance to keep them in tip-top condition, yet this is an easier job with some models than it is with others.
Our expert testers assess how easy it is to top up the chain oil and tension the chain, and how simple the teeth are to sharpen. They also rate how detailed the teeth-sharpening instructions are and how easy they are to follow.
We also rate petrol chainsaws on how straightforward they are to fill with fuel and start from cold, and how easy cordless batteries are to remove and refit.
Lithium-ion batteries always deplete and eventually die over time, and at Which?, we believe that cordless products should last longer than the batteries they come with. That's why we no longer give cordless chainsaws Best Buys if spare batteries cannot be bought from the manufacturer – no matter how good the chainsaw might be.
Once the testing has been completed, we set to work evaluating all of the results to find the best chainsaws.
A model has to achieve 73% or more to be a Best Buy and anything scoring below 45% is highlighted as a Don't Buy that we think you should avoid.
Find out which models impressed us most in our chainsaw reviews.