It doesn't always stand that girls with ultra-fake racks are gonna give an equally disingenuous sexual performance, but Big Tit Tune Up provides nothing to dissuade us of the notion. At least Karen Fisher, who's clearly not up to making "sultry" moves and google-eyes at the camera, just lies there like a lox and takes it with honest tedium. Savanna Synn holds some slight MILF appeal for those who enjoy the overage siliconized strippers.  

Only pretty Gianna Rossi and her natural pair provide any sense of authentic sexual energy — and her scene (with one of the anonymously-appointed dicks) is far from the best fuck she's ever thrown on screen. What Big Tit Tune Up manages to get right is the focus of its fixation; that is plenty of titty-humping and spooge deposits. The garage ambiance makes the whole deal seem even more mechanical than necessary.   

Retailing: Big tit/MILF filler.