So I decided to look:
FYI GT3 info is not an accurate total. I played though it 5 times start to finish and then some. I put over 10,000 miles on several of my cars in my first game save. The one below is save 5 or 6.
GT1: no surviving save file
GT2: no surviving save file
GT3: 15,965.8 miles, 677 races, 98.8%, 22 million earned, 15 million in bank, Day 555.
GT4: 6,207 miles a-spec, 15,367 miles b-spec, 678 races, 70.2%, 15 million earned, 3.4 million in bank, day 1523.
TT: 9.2% (never could get into this game)
GTHD: no info
GT5P: no info
GTPSP: 24,511.6 miles, 200+ million earned, 513,766 in bank, 1738 wins, day 387
GT5 Time Trial: no info
GT5: 89,491.9 miles, 1110 wins, 19 million in bank, day 2212. (I forgot my %)
GT Academy 2012: 165.6 miles
GT Academy 2013: no info
GT6: 8,519.8 miles, 291 races, 72%, 32 million earned, 15 million in bank, day 456.
updated to add GTPSP.