Torque is marginally higher in the 6spd. 5spd has a cheaper clutch upgrade route than the 6spd. On the otherhand 6spd is better cruiser on motorway as 6th gear will drop 70mph revs from 2500 in the 5spd to just over 2000k in 6spd - maybe the 130 boys could vouch for that?
So nothing really unless you do a lot of motorway miles?
What kind of upgrade is availble clutch wise? that was my main problem when tunning my old JTD the best clutch i could get at sensible money was from a company called Techni clutch and that dident stand up to the claims on the side of the box as it were.
Couldent put anymore than 150/60 through it,any more and you got the dredded judder and had to lift of,so the extra torqe was wasted.
In a 130tdi 6 speed, I think a lot of people are upgrading to the 130 tdi quattro 6 speed clutch - it's much more beefed up because it's for a permanent 4wd car. (It's a problem I have - where to the quattro drivers upgrade to?!)
Having driven a 5 speed golf and a 6 speed A4, I'd now go for 6 speed. not just for the motorway, but when I'm cruising at 50+, I put it in 6th and there's a noticeable drop in engine noise. Also, I think that 4th is a more responsive gear in a 6 speed car. In my golf I'd miss it out on occasion as it would sometimes seem to make a lot of noise and not much accelleration. I'd also take 6 speed because of the slight improvement in fuel economy when cruising and convincingly quick pull away in 2nd!
There you go, very biased view from me. Hope it is of some help!
A few facts on the 130hp PD engines that are fitted to A4's, A6's and Passats.
6 speed torque = 310nm
5 speed torque = 285nm
0-60 acceleration time for both is the same.
Final drive (5th in 5 speed and 6th in speed) is the same therefore no difference at cruising speed.
The 5 speed gives for more relaxed driving with less gear changes.
The 6 speed ratios are more tightly grouped which means you can access and stay in the torque band for longer (and remember they have 25nm more). Real world, the 6 speed has the edge on performace once moving but at the expense of of changing gear a lot more. Again 0-60 is the same for both.
The 6 speed box seems to be more fragile than the 5
The 5's clutch is it's weak point.
I drive an A6 with a 5 speed and am quite happy BUT I'd rather have the 6 despite the fact that it could be more problematical and that I'd be changing gear more. But saying that the 5 speed still shifts and can be treated almost like an auto, 35mph in 5th upto v-max, can't do that in a 6.
Sorry, didn't keep an eye on this thread. Sorry I can't tell you about the wuattro clutch. I've read about it somewhere but can't remember where now, but it makes sense it sould fit, but you never know.