proeasy

While my 2002 A8L is running great, with only 77k miles looking for a newer A8 (will keep the 2002 as dealer only insults you with an offer) While the 4.0 TT is a wonderful engine, you can see I put low miles on my cars but keep for a long time. While the 1 second drop 0-60 would be nice, for those that have the 2012 4.2, do you ever find yourself wanting for more power? I would plan to get the short wheel base as it is almost the same as the wheel base on my 2002 L version.

Have has turbo cars back the late 70's (Buick GNX, 944 Turbo, and never a problem, but just trying to avoid a variable I may not need.

Also, one last dumb question, are the cams in the 4.2/4.0 still belt or has Audi gone to Chains

Looing forward to seeing the new/lighter Q7 at the Detroit show

Paul O

Seaclav

Check out this thread ( https://www.audiworld.com/forums/a8-...-0tdi-2870692/ ) for some comparisons on the models.

jakematic

Hi Paul-

I have the 4.2 - wanted to stick with a known commodity coming out of D3 and the 4.0 was brand new when I bought.
Haven't found myself wanting more power, but well you know, it would be nice
Either way you'll find this vehicle a huge leap forward from D2.

It's a chain, they went back to SanityVille around 2006/2007 model year.

Also have a look at the thread Seaclav mentions.

-Jake

Lazydog

I too have an A8L and really not wanting more power. I like what it has and am happy for the most part.

derfA8L

Just came out of a 2011 A8L 4.2 V8 and now in a 4.0T A8L. The NA 4.2 V8 is a great venerable engine that's obviously well proven. My initial 1st month impression of the differences is:

The 4.0T V8 is kind of a dual personality commodity, in that it's smoother off the line vs. the 4.2 V8 in my experience---with no jerkiness when you tap on the accelerator. However, by comparison to the 4.2, the 4.0T is a tad slower off the line---I think there's a built-in programming retardation to control initial take-off torque, nothing major ala a big power dip or pronounced hesitancy that would lead to any safety concern when needing to make an emergency move (such as the "throttle lag" that has been complained about on the S6 forum), but you sense it nonetheless. Once you get rolling, however, the personality changes---not that it's a loud unruly beast---but it is considerably faster than the 4.2 engine (and that's saying something) with a ton of torque to back it up. You get up to your intended speed (and beyond) super fast, and so smoothly that you're there before you know it. I've had two prior (smaller) Audi twin turbo vehicles---2001 A6 2.7T and a 2004 Allroad 2.7T---with both registering some level of at-speed turbo lag when punching it...the 4.0T is a different experience (forgetting the power differential), with no noticeable "punch-in" lag; it just goes!!!

So far, it's been a comfortable/positive transition for me from the 4.2 to the 4.0T. I didn't need the additional torque or the extra 63 horses to keep me happy...my lease was up and I just couldn't do the 3.0T V6 in an A8, so it was the 4.0T. If I didn't lease and was going to hold on to the car beyond the warranty stage, I would have some concern regarding the engine plumbing complexity and durability related to the twin turbo layout, but what can you do...it seems to be the way of the world these days.

Either way, they're both great engines---just a bit different in how they work their wonders :^)

Edit--BTW, in as much as you're coming out of a D2, IMO the big differentiating factor going beyond either the 4.2 or 4.0T variants is mating them up with the 8-speed tiptronic tranny, which does a marvelous job of converting both engines' power into speed.

kgd_007

I went from a D3 S8 to the D4 A8L 4.2. Don't notice acceleration difference as they are about the same but I do notice a difference in handling. The S8 seemed much more nimble. If I ever decide I need a shorter car again I will likely move back to an S8 probably more just to have the power even though I don't miss it right now.

Jack88

If you can afford it, I'd say the 4.0t. From a practical standpoint, more available with lower miles and more warranty left. Much more importantly, however, you really can't have too much power.