I am a better mechanic than many who do it for a living, which is just one reason I do my own work.
+1 Sometimes when I see the shoddy quality some shops do, I thing the best mechanic I know is myself.
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Caring wise I am at least a 5 and maybe even a 6. If there is a best quality way, fluid, and or part, that is what is done/used to do a job if I do it. I have a ( 1/2 inch and a 3/8 inch and a 1/4 inch ) drive torque wrench, and there are plenty of " mechanics " who do not even know how to use one. I have seen way too many repairs on my vehicles over the years when I let others work on them where something was not done correctly, or tools were left in the area the work was done, or it could of been done better. That certainly is not going to happen if I do a job on my vehicle.
Knowledge wise I am usually a 4 but that varies between a 2, 3, 4, or 5 depending on what the job is. I certainly will do my homework and learn as much as I can about doing a repair that is something I never have done before, before I do it if that is the case. Lately that has been YouTube most of the time. And one thing about YouTube is you must watch several videos. There are sometimes one or more things someone does someway that is not the best way of doing it, and others show better ways of doing it. And there are also a few who have no idea of what they are doing and still post a video that they had no business posting because they were totally wrong, such as one young man who though he knew how to set a torque-wrench and was totally wrong, and went on to preach his incorrect way of setting one.
Actually doin a job, I am a 3 because I only do a job myself now days if the weather permits, because I do not have access to a garage anymore, and work on my vehicle outside. And that limitation, along with my bad back limiting when I can actually do a job, along with just finding the time to do a job, has resulted in me doing less of the work myself over the years. So I am not doing enough work often enough my self to be as competent as I could be if I did all the work all the time. When I was in my 20's I was not limited by my back, and had access to a nice 4 car garage that was 2 trucks wide and 2 trucks deep and therefore did more work on my own vehicle myself.
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I still remember the time I welded the frame rails of a replacement back bumper and rails onto a friends car and it was later totaled by being slammed in the back, and he told me about it and that everyone of my welds held. When we did that job, I had him V grind EVERY junction of old meets the replacement newer metal, and then I filled in the V of each with a gas welder because the electric was broken at that time. When welds are abused like that and they all hold, something was done right.