Review on 🔧 Shankly Compression Tester: Professional Grade for Domestic and Imported Cars, with 14mm/18mm Short Adapter and Flexible Adapters by Anthony Robichaud

Very inaccurate, not recommended. This was used to test a 2013 Subaru Legacy with an engine under 60k and no known engine issues. No burning or oil leakage, no power issues, dealer tested. Tests showed more than 40 psi below expected levels. In the 135-140psi range when the spec is 185+, tested multiple times on multiple cylinders. Rented a cheap pressure gauge from O'Reilly and the numbers were much closer, 165-170psi. The unit also had small nicks and nicks all over it that looked either used or mishandled when assembled. The device's design made it relatively easy to connect the cylinders, but there's not much point in a sensor giving you the wrong numbers. I guess I'm saving up for a better one.