The filter of choice for the TR's is the AC PF-52 for it's extra capacity, so
being that most owners consider this a good filter to run on these car's (as do
I) and that the TT/A engine is the same, the below filters will be compared to
this one.

AC PF-52;
8 piece construction, no safety bypass valve
4 7/8 tall
36 pletes
media with caps= 4 3/16 x 2 11/16
shell= .015 thick
drainback valve= heavy construction, .075 thick, also used to compress media
firmly into shell.
element= 4.250" x 50" = 212.5 sq. in. to filter (important to remember this when
comparing)
steel end caps

NAPA 1086
9 piece construction, no safety bypass valve although box indicates one might be
contained
3 1/2" tall (extremely high clearances to frame, FORD metal arrester also easily
installs)
65 pletes
media with caps= 2 7/8" x 3 1/2"
shell= .015 thick
drainback valve= heavy construction, .060 thick
element= 3" x 94" = 282 sq. in. to filter
steel end caps with heavy steel spring at bottom of shell to hold element VERY
firmly into anti drainback valve

AC 1218
8 piece construction. no safety bypass valve
5 1/2" tall
36 pletes
media with caps= 4 9/16" x 3 7/16"
shell= .015 thick
drainback valve= heavy construction, .075 thick, also used to compress media
firmly into bottom of shell.
element= 4.5" x 67" = 301.5 sq. in. to filter
steel end caps

FRAM HP4
11 piece construction
5 3/4" tall
65 pletes
media with cardboard caps= 4 1/2" x 3" tall
shell= .020 thick
drainback valve= rubber seal only .030 thick, steel support with cork gasket (3
pieces)
element= 4.375" x 87" = 380.625 sq.in. to filter
cardboard endcaps
uses stamped pop metal bung at bottom of shell to support media into anti
drainback valve

I contend the best filter to use for the TT/A is the NAPA 1086 due to
construction, sq. in. of filtration and clearances to the frame. Filtration is
only 19.5 sq.in. less than the larger 1218, but it's also 69.5 sq. in. larger
than the PF-52. The 1086 is a better filter in many way's than the PF-52, so
why is even more filtering media needed? However if TT/A owners really feel the
need to go ballistic with oil filtration, the longer version of the 1086 in
available with NAPA PN 1186, but like the the 1218 and the HP4 safe clearances
to the frame will be sacrificed. I don't see the need for a longer filter on
the TT/A especially when you consider how much better this filter is than the
long PF-52 filter is for the TR's, consider how much more than the short PF-47.

John Pearcy