Tuesday

I just made my first payment and have already exceeded 7,000 miles in this car. I left the morning of the 21st from Orlando, Florida and arrived in Los Angeles the evening of the 22nd. Not one issue during the drive - in one part of west Texas the temp dropped down to 26 degrees! I had ice forming on my mirrors and windshield trim. Oddly at that elevation (over 4,000 feet) and temperature I could not seem to get a over 28mpg - when 35/36 is the norm.

Audi is not exaggerating that you can get 800 miles to a tank, I've seen it. If you're like me and mostly cruise the interstates at 80/85 you'll see closer to 700ish - but that still means you watch everyone else get off for gas when you still have 300+ left in your tank. It's a good feeling.

I have driven the country twice in this thing and plan to take a lot more trips.

If anyone is wondering about drivability, economy and power I can assure you that this car is a contender. I traded in a 450hp BMW (2013 650i Gran Coupe) for this car and thought I may miss the power. Not one bit.

I guess this is a pointless post for all intents and purposes - just wanted to share what an extraordinary vehicle the A8 is paired with the powerful and thrifty 3.0 TDI.

jakematic

Not at all... good info for those of us considering the TDI.

s5blitzer

Welcome to the world of TDI. Glad you had a fun trip.

perlfather

We are now driving an A7 TDI after a '06 A8 and find the TDI just amazing. The perfect car for the US where acceleration is important (428 ft-lb of torque) rather than top speed (hp). It is also helpful that all the torque is availability at low RPM. For those of us that do not drive our cars at 6000RPM this is so much more fun and satisfying. The difference to 60mph on the A7 between the gas and diesel is 0.1 sec!

Gkef90

Sounds like a great car. My only complaint is that for now you can only get it in the LWB. When you add the cost of the LWB and the Diesel, it didnt pencil out for me. I would have looked at it if it was in the SWB. However, I do believe Audi will be releasing the TDI in SWB in the future.

jerryg05495

Just got an A8 TDI this week, I put on some snow tires, though the selection for the 20" wheels is quite limited. Only have about 300 miles but really enjoying it.

Thanks to everyone on the forum for all the information and helpfulness.

jerry

in2dwww

That's what the A6 is for! I ordered an A6 TDI and I can't wait. Once you go diesel, you never go back. I have owned two VW TDI models in the past and currently have a Mercedes bluetec. The A6 has all-wheel-drive and I think that makes the car indispensable. If I had the means, I'd grab the A8 in a heartbeat.

Tuesday

It's fair for me to update this thread by adding that just after 10,000 miles an Exhaust Gas Temperature sensor died. I got a service engine light and pulled out code P0544 and P2080 - both pointing to sporadic readings from EGR bank 1 sensor 1. I ordered the part but it will take ages to get to me due to the holidays. Until then I plan to pull the sensor for a visual inspection since a lot of VW guys reported that these codes corresponded with not only a faulty sensor, but a physically damaged one. I have to look at one to see, but it appears that some of these sensors are made with ceramic parts that crack. I can completely understand how mine could fail so rapidly considering that my road trips often consist of ~20 hours of almost non-stop driving each day. (Doesn't last for more than two days though because you run out of road and meet a new ocean).

I am totally positive the more TDI owners will encounter this problem as they rack up miles. I am betting you're all about 6 to 10 months behind me in mileage accumulation, so keep your eyes on this thread as I update my progress and document my discoveries.

For the record, the part number for EGR bank 1, sensor 1 is: 4H0906088L

They run about $130 and are in stock in the NJ warehouse. It is a warranty item, but I would pay double that to not have to set foot in another service department and drive another depressing loaner. The car still runs perfect, no decrease in economy or power. I am taking it easy because without a proper EGR reading the DPF could be at risk.

Tuesday

EDIT: I used EGR when EGT is the proper acronym.

MP4.2+6.0

Owning a D3 and maybe eventually getting a D4, I toyed a bit with a TDI idea since it gets into the torque arena of something like my W12. I get the mileage improvement hands down, especially from my current ride. But....

I got a 2013 Q7 TDI loaner this week while the recent 2013 Q5 Hybrid purchase was in for a repair. Only about 2500 miles on this loaner and clean (new looking) inside and out. I generally like getting different dealer loaners for informal extended test drives. Sometimes great to try like the 4.2 D4 I had for 4 days and a couple hundred miles, sometimes a "no thanks" like the CVT rubber band mobile I got once in an A4, sometimes a "so this is the 3.0T" like when I got the late C6 run 3.0T A6Q. But frankly, I walked away from the Q7 TDI thinking brutally honestly, what a piece of crap, and why did they put this in the loaner fleet for anyone but a Q7 owner. Other family members who like Audis thought similarly. The Q5 is no A8 handling wise, but compared to the Q7 it's a sports car. And I know the Q7 is a big time porker, worse than the Q5 and the A8 or bigger motor A6's. Nonetheless here, I'll focus on just the TDI aspects that I expect likely cut across the models, and try to ignore the Q7 specific shortcomings and now long in the tooth stuff I can easily spot as a many generation Audi owner.

Yes, I loved the torque... when it appeared that is. There seemed to be both a good amount of lag, and inconsistency. Seemed to really want to pull big time if it was solidly in a gear or if it stepped down once. But throw in a switch from off gas to on gas after some trailing throttle or maybe several gear changes if you pushed into the pedal rapidly, and it was more like the old "one-thousand one, one thousand..." stuff. All resulted in a non-linear feel too, admittedly compounded by the Q7 porker weight.

A bit of an aside, but I did get on it leaving the dealer right next to the freeway in the morning cold. There the pull was reasonable--not astounding given the porker weight and not up to my Q5 Hybrid even, but I figured if the motor was in a lighter vehicle like a Q5, A6 or A8 it would show better (especially the Q5 TDI with yet a bit more juice than the others if you look carefully at specs). But then there was the oddity of a definite exhaust cloud out the back window... Haven't seen that since my 67 Chrysler T&C yacht mobile high school ride with the 383 and the Carter 4 barrel AFB carb; interesting though it seemed like it was a lot of steam since it was fogging the rear window. My 6.0 W12 can cook up a whole bunch of steam to match most anything in the cold, but I don't see it out the back when I get on it, cold or otherwise.

Then there was the vibration. It was pretty well noise insulated, other than when cold where it was fairly easy to hear the usual diesel valve train sounding clatter. I have also heard a presumably warmed up Q5 TDI on a slow speed drive by walking in the neighborhood, and it won't pass the fine sewing machine sound test either. But, I could still be fine w/ that, and maybe can guess the A8 TDI is yet more insulated inside, as is the D3. But, back to the vibration, I felt it in the steering wheel at idle, and even in the pedals. Meaningfully so, and unmistakable. Much worse than my Q5 with the 2.0T four banger, and worse than my old 2.8V6 and certainly 4.2 A6. That really surprised me, given I would have thought with things like modern electrically assisted motor mounts it would have smoothed out a lot, plus its a V6 not a four. Maybe the A8 has stop start to hide it some?; the Q7 did not.

So, I would like to like it, but my Q7 TDI intro was memorably bad. I have been kind of hoo-hum on the D4 originally (styling, trunk, the usual questions), but as the motors advanced from the 4.2 to the 4.OT and even the 3.0T, I have liked more the drivetrain performance side. My four day A8 4.2 loaner drive back a year plus back left me a bit underwhelmed by the 8 speed, albeit I get the MPG and performance benefits, and it seems like they are now getting the shift programming better. In the Q5 it's now good, and given that is a Hybrid it is actually a high torque set up. Going to take a serious look at the D4 when the refresh rolls out in coming months. I like some of the styling tweaks, and the apparent trunk tweak. Especially with the apparent power bump in the straight 4.0T (per the Euro release) that closes the gap on the S8 a lot and pushes it beyond even the more highly tuned W12, let alone my older one. I've thought about the TDI yet more recently and might have done it on the Q5 if it was around for US models in 2013. But with that Q7 disappoint and wake up call I think I may want to look more at the 3.0T if I wanted somewhat more MPGs, without the AdBlue, the items above, the somewhat higher U.S. diesel cost (at least here in CA), etc. My own instinct is if the venerable 4.2TDI ever got here, then I would be in line.

Net, tell me more, and give me an honest assessment focused on NVH and of the linearity and responsiveness of the 3.0 TDI torque curve and turbo lag.