Just to add a bit more 'meat' to Tom's comments on fuel consumption -
...MikeMars posted the 'onion curves' for the 1.9TDI somewhere on here.
...Surely enough, if you try to drive too slowly in 6th gear, the engine starts to chug and the load reading goes up, resulting in more fuel being burnt. ...
Having been given a 6 speed A4 TDi for a courtesy car this morning, which turned over at 2000rpm at 70mph, I now really want a 6-speed A2! Argh!
I find that the sweet spots are:
* 1250rpm for very low load (downhill, steady low speed driving, etc),
* 1400rpm for steady medium loads
* 1750rpm peak efficiency (gentle hills, 60mph, 197BSFC on the chart)
* up to 2000/2200rpm when you want to accelerate (torque peak)
As Spike says, it is stressful for the gearbox to be at low rpms & high load.
It seems that we have common view and understanding here and figures seems very reasonable for remapped car (I assume).
Yes Maso, based on my experience with 1.9TDI remapping is must thing for smooth and relaxing driving. In my opinion only correct way to do engine tuning is remapping with Dyno or similar equipments where curves can be mapped individually for every car. I have no experience of "general chips/programs" which are just installed to car but not tuned up, except somewhere from year 2000 when curves were too agressive and not comfortable to drive in my friends VW TDI. For sure they are better that factory tuning, but at least in Finland there is no difference in price (almost not at all) and in general I do trust more the professionals (anyone can purchase needed HW and start to install some general maps without real tuning). And at last but not least, why not to do tuning by correct way when start to do it
Nice colour match I think...
View attachment 11668
One of the many jobs which Vince did for me last Friday
Please don't tell me you need a six speed to get illumination!
Have you got mood lights/downlights with the interior lights as well?
Tom, do you think you've seen any improvement in MPG since going for the big 6?
Yes Dan, I have, but it's hard to be objective about it because I've done the upgrade in the middle of winter.
My most regular place of work is only 6 miles away. Given the roads between there and home, I was limited to 4 gears when I had the longer 5th. On that journey, I'm now able to use 5 gears, so I'm sure I've seen an improvement there. That said, the engine barely warms up, so those journeys are always guzzlers.
I've done a few two-hour return trips to Manchester Airport and Liverpool on the motorway and it would appear that I'm getting the same number of miles per quarter tank as I was with the longer 5th... but in near-freezing temperatures.
When the warmer weather returns, I'll be able to do a more objective comparison, though based on the evidence so far, I'm confident that my personal best efficiency records will tumble.
However, I'm delighted with the mod anyway, if only because the car's driveability is so much better than it was with the longer 5th. Perhaps the most remarkable thing about having 6 gears is how underwhelming it feels. And I mean that in a good way. It's just so intuitive. It just feels right. With the longer 5th, there's no forgetting which gear you're in because you're aware of the large gap between 4th and 5th. With a full set of 6 gears, I once again just change gear as needed, without giving it any conscious thought. When a mod makes you think the car should have left the factory that way, you know it's a good one.
Tom
I do now!...