Originally Posted by SierraBravo
Maybe because the car is suppose to be left in cruise control for it to work. Just know that I have been able to get some impressive mileage on the highway and would like to keep it that way.
From the A6/S6 Product info book (page 6)
" V4 mode uses cylinders 1, 4, 6 & 7 & is accomplished by an electromagnetically controlled camshaft which rotates into a zero lift camshaft profile; the other cylinders are shut down & fuel injection/ignition halted after first taking in air to act as an air spring for reduced power loss.
V4 transition will occur in a fraction of a second under these conditions (coolant temperature of 86 degrees, 3rd gear or higher & between 960 & 3,500 rpm). V4 mode can last for up to seven minutes at which point all cylinders are engaged to prevent excessive heat loss & efficiency."