There is a $4k difference between the T5 and T6 (10% premium): It seems like most people are opting for the T6 or T8. I was wondering what made you decide against the T5? If you test drove it, were you able to easily tell the difference in drive performance?
PS, I did use the search function and found no threads on the T5 vs T6
I actually commented on this in some thread before, but I can't find mine so unsurprised you didn't.
My calculator says the XC60 MSRP T5-T6 price differential is $3,400, not $4,000. Still significant $$.
Only tangible changes are the supercharger, a larger fuel tank to feed the thirstier beast, and 1" larger brake rotor diameter to handle the extra weight of supercharger, tank, and extra fuel. My observation was that both T5 and T6 were quicker off the line than most SUVs, but the T6 was noticeably quicker. Punching the throttle while driving, however, the T-5 vs T6 difference was negligible, particularly in dynamic mode. My impression is subjective, but consistent with the design differences. The supercharger disengages in the low-mid rev range after the turbo spools up and takes over the boost job. So after disengagement they are basically the same engine, except the T6 is carrying extra dead weight of supercharger and fuel. Somebody else here can probably clarify if the engine electronics tuning makes other adjustments I don't know about.
Bottom line for me: I retired from the Stoplight Grand Prix after high school, and a family SUV isn't dusting off any Lambos anyway, so T5, and save the $3,400 and the gas. T8 is super cool, does let your Inner Teenager dust off garden variety SUVs and sedans (avoid AMG, M, and S badges). If your driving habits let you go all-electric, way cool. But for most of us, cost-ineffective even after tax incentives. Very complex, a pain to charge in many parts of the US, and 500 lbs of extra weight certainly doesn't improve braking and handling.