Maximum Bleed for 8.5"x11" Sheet?

[Ronald]

My client wants to print a full-bleed plaque design that will go in an 8.5"x11" frame, but he wants to print it on 8.5"x11" paper since it's cheaper than 11"x17". I know this is an amateurish question, but what's the approximate maximum bleed I can achieve on 8.5"x11"? I looked it up online but it turns out I have a lot more leeway than I thought, at least with one printer I used. Then I emailed one of the people at the print shop about it and they instead told me the general rule for bleed compensation (adding 1/8th of an inch) rather than telling me my potential outcome for starting with 8.5"x11". Do all printers have different gripper edges and therefore different results? It's probably not a big issue but I'd just like some more answers for further insight.

Thanks.