I agree w/ Genesis. My 6v92's are on the Great Lakes. They have 3300 original hrs and they still fire quickly, even down to mid 60 degree temps. Even at colder temps, the smoke clears within 30 seconds. If you have a bad injector then the test will obviously not tell you anything about compression, but this is just a quick test that is supposed to tell you if you need to dig deeper or not.