Compression tester VS Leak down tester, Which one to buy? Options

[UVZ164]

Hey guys,

Looking at expanding my tool collection with either one of these two.
The leak down test provides more comprehensive results as to where leaks are and exact percentages of cylinder leakage.
But the compression test results seem to be what everyone uses in terms of a PSI number.

My question is if i use the theoretical value of compression provided by the BGB which is 178 PSI (5s-fe engine) and i use the leak down tester and get a cylinder leakage of 10% can i just deduct 10% from that 178 PSI and get 160.2 PSI compression?

If that way works i guess ill get the leak down test if not i need some opinions on what to get.

Thanks,

Reece

[Spider77]

Compression testers are just overall engine health. Where as a leakdown tester should let you know how much and from where your loosing compression. If your just looking for PSI range and ease of use, get a compression tester.

[Syaoran]

Compression testers are just overall engine health. Where as a leakdown tester should let you know how much and from where your loosing compression. If your just looking for PSI range and ease of use, get a compression tester.

Yes, I forgot about that detail... Compression testers are very straightforward and only require your remove spark plugs, whereas the leakdown testers are a bit more complicated.