physical size of the outer filter body has nothing to do with whether a given filter will "work" in a given application, by itself. It's what is inside that counts. Material, density, micron rating, check valve (or not) and whether the application needs one (or not) thread diameter and coarseness, and location/diameter of sealing gasket are what counts.
Lets talk oil filters for a minute. just for arguments sake. All of my vehicles call for a Fram PH16/Wix-Napa 51085. but that doesn't mean those are the "only" ones that will work and not cause damage. I could use a PH 2835 (many of our Briggs and Kohlers with remote filters can use these) but it is physically about 1/2 the size. which only means that it has less capacity and will potentially plug sooner. but before it gets to that point it will work just as good as what is "called for".... Nest up in size from the "called for" filter is a PH43/51068. same as called for but slightly longer can. so slightly less likely to plug. then we have the FL1A, PH8A,PF2,etc.... (all different brands but same filter as each other-- I think WIX is 51115) again same diameter as stock, same filter media, thread size, gasket dimensions, etc, This is the one I like to use when space permits. Larger yet, more capacity to trap dirt, less yet likely to clog due to size and area within, etc.... but they will ALL work as will a PH 400, again skinny can but longer than PH 2835.
Often the only difference/determining factor is room available for the filter. truth is there is ALOT of consolidation that could be done, lots of filters that could be discontinued and guaranteed, there WILL be alternatives that will fit and filter just the same as what may have been "called for" many years ago. There are some "hydraulic" filters that are identical in every way to an "oil filter" except for the markings because people have the idea that it is the "only thing that 'can' work for this application. why would a filter that works on a Sundstrand 15 in a Deere NOT work on a Cub with a Sundstrand 15? Same hydro. Ariens, wheel Horse, and so many more use the same hydro as one another, and yeah they may call for different fluids but at the end of the day, if we are talking the same unit, no matter what brand the tractor may be, then the same fluid and filter that will work in ne will work in the other. The biggest issue here is not to mix them, if you want to use something different, don't just "top off", change it out completely to your preferred fluid.
