roadkill

Ive got a new 2011 A4 with the 8 speed tiptronic automatic. While I'm coasting at 50 kph or so it will downshift and acts like a gentle brake instead of feeling like it's in neutral and just coasting. Is this normal? Thanks!

plg_cp

This would be normal behaviour for a manual transmission...if you downshift then you'll slow down. One of the benefits of manual tranny. Maybe the new tiptronic is designed differently than previous autos.

roadkill

true, but it's an automatic. I'm not using the tiptronic, just letting the car do it's own auto thing, and it still is downshifting and slowing down. Thats the part I'm wondering about.

mikeh

With a name like Roadkill maybe its not such a bad idea to slow down.....LOL

A4Avanti

My B6 CVT automatically slows down too, its not a coaster thats for sure and i kinda like it. I just let off the gas and it slows down faster than other automatics thats for sure.

jamieta430

my 2002 a4 tiptronic does the same it will downshift as you slow down. it is even more noticeable when in sport mode.

thecrave

Noticed this on the 2011 Q5 2.0T 8 spd. Thought maybe something was wrong. Seems like I would get better gas mileage if it would let me coast.... Kind of annoying.

jfo

The primary design objective by ZF for the new 8 speed was to achieve the best possible fuel consumption. While intuitively your comment makes sense, there must be a good reason for this shift pattern when coasting. Perhaps the affect on consumption is marginal.

More info on the 8 speed...
ZF Friedrichshafen AG | Fuel saving and minimizing CO2 emissions

thecrave

My guess is that the mileage improvement noted by ZF (11%) has more to due with the extra 2 gears over the 6 speed. Thanks for the link!

Interested in what others are finding with this transmission as well.

a4audi4fun

Assuming you have the instantaneous fuel consumption trip computer option, look at the numbers when you are coasting downhill. Most modern fuel injected engines stop fuel flow completely when coasting, so the figure shows 0.0 l/100 km. Certainly that is what shows on my 2005 A4 3.0 and 2008 A4 Avant 2.0T though I do have manual transmission on both - means no fuel being burned while coasting, hence improved overall fuel consumption.