2009 Audi S5: Cruisin' & Downshiftin'
October 09, 2009
Our long-term 2009 Audi S5 has a manual gearbox. It has cruise control. Those things by themselves are not remarkable.
The way they interact, if not remarkable, is unusual. Once set, the S5's cruise control does not cancel if you decide to downshift. The S5's cruise control resumes your set speed as soon as you've completed the gearchange.
This took me by surprise at first, only because so few manual-gearbox cars allow this. Typically the cruise cancels when you dip the clutch.
Because I'm a geek, I began thinking of what might drive an automaker's decision to adopt this "clutch-resume" strategy (as Audi has) over the usual "clutch-cancel" one.
Pro: On a steep freeway grade that requires you to drop down a gear to maintain your speed, "clutch-resume" allows you to do so without having to hit resume afterwards. One less button-press in this case.
Con: Downshifting for engine braking in a "clutch-resume" car requires you to hit cancel first, else you're in for a surprise when the car tries to re-accelerate to your set speed! One more button-press in this case, or use the brakes.
Any geeks out there that can think of other pros or cons to either approach?
Jason Kavanagh, Engineering Editor