Hand Tigten only?

[Jegisx]

I am in a slight bind and I am trying to get peoples view point on a technical dilemma.
First let me a little background so you understand the reasoning behind this post and subsequent question.
I worked for almost 2 years at a chain store garage doing alignments, oil changes, wheel bearing, tie rods, etc, basic stuff. The rule the company had in place didn't allow us to use oil wrenches to tighten oil filters, every thing was hand tight with only a few exceptions made for certain vehicles were the filter was hard to access by hand.
However, I recently changed over to a dealership hoping to learn more and enjoy better working conditions. The problem lies in that when I switched over I kept doing oil changes as I was taught at my last job because 1) that was they way I did it for almost 2 year with not a single issue or problem and 2) the dealership I now work at never verified any of my training to see if it was in line with how they do things in their garage and never informed me of there standard operating procedures, etc, etc.
I of course not having the same level of experience and never having a single issue/complaint with hand tightening oil filters continued to do so at the new job. Now the issue -
2 months into the job they started having a few customers come back with loose filters on their trucks, 2 customers at first. I was informed that I wasn't getting them tight and need to use a oil wrench to tighten them. No problem, just let me know and I will fix the issue, which I did, problem solved. But I was again @ 2 months into it before they told me this and at 4-7 cars a day it may add up. Since then they have had 2 more come in and are threating to let me go if any more come back, I informed them of reason #2 as I stated above. I'm still waiting to see how this next week goes, esp. as I really enjoy the job.

What's irritating me is I can't figure out what the difference is between the hand tightening of the filters at my old job and the having to use a oil filter wrench at the current one. The only differences are 1) the avg mileage for a vehicle at my old job was @120k where this is @50k and 2) the old job used Fram and Champion filters as a whole and this one uses almost exclusively AC Delco.

Is hand tightening normally enough? Or is a oil wrench tightening the standard? Does the filter manufacture make that big a difference?

[Black Lotus]

The last filter I installed had instructions on how to tighten it--3/4 of a turn from when the seal first made contact the engine. Supposed to hand tighten only. (good luck getting your hand in there to do that) I used a band strap type wrench.
Other filters I install get hand tightened, then add another 1/4 turn with a wrench to "make sure".
Second method isn't very precise, but I haven't had any filters leak of fall off, and I can still remove them.

[vgames33]

I crank them down by hand until they won't turn any more. I use a strap wrench in certain situations, mostly on GM trucks where I can't fully grip the filter to tighten it. In those situations, I tighten by hand as much as I can, then go about 1/2 turn or so with the wrench until it feels tight.

3 years and zero comebacks.

[6000wagonman]

The filters I use say tighten 3/4 to 1 turn. I make a mark on the filter that I can see when it's gone around 3/4 turn and tighten it 3/4 to 1 turn regardless of what method I have to use to do it.