Do engine compression readings ever match the book?

[Olderisbetter]

I have 2 identical gunson testers and i tested them on the same engine and they gave different readings, But the cylinders showed almost the same readings on both, Aslong as my engines run ok and don't burn much oil i am happy, Sometimes i have engines ready low but after a flushing oil goes in then a decent oil after they improve a fair bit.

 

[rcx132]

Thanks for all the tips.

So some of you are also saying you don't get book readings and problems with low cost guages. The 140 psi is plenty for the engine to run properly, I'm pretty sure the 40'000 miles on the car is genuine so I'm not going to worry about compression, esp as all cylinders show the same.

Engine isn't running good, I'll post up what I've tested later once I've done the ignition timing.