siptrunk

I have 2014 A4 Prestige Quattro Tiptronic and have a couple questions.

1. When I slow down (in Dynamic or Normal) I feel it downshifting and see the RPMs spike each time it downshifts. I'm talking 20mph and under. This is the first car I have felt do this under normal driving conditions. I usually notice in start and stop traffic where the car is moving slow and I'm either not braking or lighting braking.. In my other cars I can hit gas and then coast until the car stops. This car I can feel the gears changing and see the rpm spike. Is this normal?

2. When on the highway the car wants to drift to the side requiring me to constantly recorrect. It makes highway driving very stressful. It almost feels like wind since the road is flat and the wheel is straight but the car wants to move sideways. The dealer checked alignment and found no problems. Are there any known issues with this?

dscline

1. Normal.
2. Not normal.

siptrunk

Dscline,

Thanks for responding.

1. Is that feature of tiptronic ?
2. Has anyone successfully fixed this problem? I did some searching and have found others with similar complaints.

dscline

For #1, my personal belief is that it's done to maximize fuel efficiency. In my previous B5, which was a manual, it became apparent that the FI system cut fuel on deceleration as long as engine speed was below about 1100-1200 RPM. If you let off the gas, the MPG gauge would go to "--", indicating no fuel was being delivered. Once the car slowed down to an engine speed of 1100-1200 RPM, you could feel a slightly less engine braking, and the MPG gauge would again start registering fuel consumption. On my B8 tip, I notice the same behavior, but it generally downshifts just in time to keep the engine above the point where it resumes fuel. At least until it gets down to 2nd and 1st gear. In those gears, it lets the engine continue to dip below the typical 1200 rpm downshift point. My expectation there is that once the ratios get that high, the engine braking/jolts are more noticeable, so they give up some economy at the two bottom gears to make the driving experience smoother.

At least that's how mine behaves.

For #2, I can't help: mine doesn't do that, and I wasn't aware it was a common issue.

roger_1

IF the alignment is correct, and tire inflation left and right are equal (you have checked that, right? ) then you may have what is referred to in the industry as 'radial pull'. Try swapping one left side tire for one right side tire, and see if there's a change. If not, swap the remaining two. If still no change, check the alignment again. BTW, if the tires are directional, do not leave them installed on the wrong side.

Of course, it could also other things - a frozen caliper or something, though presumably you'd be aware of that.

Your car should NOT consistently pull left or right, on a level road, with no significant wind.