GTD+

[monkeyhanger]

Definitely need to get it up over 3000rpm, not all the time though. I have been treating the car a bit meaner (only when the oil is warm) over the last few days and not seeing my mpg suffer as a result. My Scirocco definitely benefitted from not being babied early on. It felt a lot more powerful than the 170PS it officially was.

I asked TDI-tuning.co.uk for a return authorisation on their box. With my sh!tty Bridgestones not being able to put any more power than stock down in the damp and no true mpg gains seen, i'm not really bothered enough to want to keep it and pay £80 a year extra on my insurance for the privilege.

I was very complimentary about the box's power increases, but said I just wasn't seeing any true mpg gains and this was my main motivation for buying the box. They want me to discuss this on the phone where i'm sure they'll advise me to stick it on setting 1 and see what happens. Don't see the point of that, 8PS increase over stock and possible small mpg gains for the privilege of paying £530 over 3 years between the box and insurance enhancements - the box would have to give me 12% mpg gains to pay for itself.

Thanks for your email. We are sorry to hear you are not happy with the improvements on your tuning box, we are very saddened to hear this but we are very confident we can get this resolved for you so that you start getting performance and economy gains. Please could you give us a call so we can discuss this further.

The only way I could see them being able to improve anything would be to give my car a custom set of maps tailored to my car, which would mean driving it all the way down to Essex so they could make the changes.

[monkeyhanger]

Just spoke to TDI-tuning about the return of my box. They want to bring it back for “tweaks” to the on-board maps. They say they can get me noticeable mpg increases by tailoring the box to my driving style if I give them a description of how I drive, what road speeds I generally encounter etc. This is apparently the next best thing to them physically having the car there at the place.

The guy had plenty of patter about how these normally go out on the standard maps and work wonders on both performance and mpg. I just can’t see the mpg gains happening even though I see huge performance gains.

He’s going to allow me a further 2 weeks to appraise the tweaked product after I have sent it back and he has returned it to me, but I really think I’m wasting my time expecting actual mpg gains. I’m convinced most people reporting higher mpg from the use of these boxes are just reporting MFD readings that get ever more optimistic as the ECU underestimates what fuel is actually being used.

[CraigW]

I don't profess to knowing much about how these boxes work but i would have thought that the outcome you are looking for (i.e. greater performance with significantly increased mpg) is not possible. Surely in order to achieve good performance gains the engine is going to have to ignite the petrol/diesel much quicker (not very technical) which is going to have a detrimental impact on economy.

It seems that your overriding priority is an increase in mpg so perhaps you should try the box on the lowest setting and see what impact this has. It may be that the gains are so great that the box does make sense to hold on to.

However, i was under the impression that the vast majority of people buy these boxes for the increased performance gains and provided it doesn't have a huge impact upon mpg then its doing its job successfully 

[monkeyhanger]

They do adverise both mpg and performance increases (not at the same time). Drive sensibly and you should see an increase in mpg, make use of the extra power and you won’t. I wasn’t making use of the extra power in my experimentation week and saw my actual mpg stay static – pointless. Indicated mpg went up as actual fuel usage and the ECU’s presumed usage were 2 different measures.  If I was getting an actual 50mpg around the doors as I expected then I would be happy to make use of the extra power at a slight economy penalty.

The only way I know that you get more power on tap and more mpg together is to make the car more efficient with any given quantity of fuel. I really believe now that all these boxes can do (even the sophisticated 2 channel ones) is chuck more fuel in per injection cycle and increase boost pressure slightly to up your performance. If they can’t make for a more efficient burn (more efficient homogenisation of fuel and air) then they aren’t going to use any less fuel, but could falsely increase the MFD indicated mpg.

Why am I even giving this another go by just sending the box back for reprogramming at my expense rather than getting my money back? If you are only interested in power increases then don’t let me put you off, the gains there are amazing (more than my Bridgestones can handle in the wet).

[Buddy]

That'd be a shame MH but you've generously shared your reasons and in your case, I can't disagree with your rationale. I've yet to send mine back for a dual channel swap out. My single channel unit has been on top whack for a while now and if anything the power delivery has improved slightly more.

[mcmaddy]

I know people say it's a waste of time but over the last 2 days I've had the car in eco mode while doing my usual work trip. mpg is better than in normal mode so I'll leave it on for a few more days around town and see what happens.

[monkeyhanger]

Eco did nowt for me - just ended up pressing the throttle harder to get it to do the same thing. It seems to only dull the throttle response rather than make the car run on a more efficient map. If you were using your aircon then it would make a difference because it would ensure your aircon was i eco mode. If you had DSG you might find yourself freewheeling in neutral to save fuel too. I run on individual with everything set to Sport except aircon which is set to eco. Your mpg increase might have something to do with switching from V-power to standard Shell. I will definitely have to switch.

Will be interested to see what the tweaked box will feel like when TDI-tuning send it back (posted it yesterday, should arrive there Monday).

My performance measurement done last night on an empty Coast road. Passed the marker signpost at 79mph. My 170TDI Scirocco passed it at 83mph, and the 140TDI Scirocco before that passed at 78mph.  Do I have a 160PS GTD or did I have a 190PS Scirocco? Maybe it's the V-power, as previous VWs were run on standard Shell.

After that i'm again quite serious about keeping the box just to have a car that actually performs better than the last one despite already supposedly having a 15PS advantage.

[Skinnee D]

Eco did nowt for me - just ended up pressing the throttle harder to get it to do the same thing. It seems to only dull the throttle response rather than make the car run on a more efficient map. If you were using your aircon then it would make a difference because it would ensure your aircon was i eco mode. If you had DSG you might find yourself freewheeling in neutral to save fuel too. I run on individual with everything set to Sport except aircon which is set to eco. Your mpg increase might have something to do with switching from V-power to standard Shell. I will definitely have to switch.

Will be interested to see what the tweaked box will feel like when TDI-tuning send it back (posted it yesterday, should arrive there Monday).

My performance measurement done last night on an empty Coast road. Passed the marker signpost at 79mph. My 170TDI Scirocco passed it at 83mph, and the 140TDI Scirocco before that passed at 78mph.  Do I have a 160PS GTD or did I have a 190PS Scirocco? Maybe it's the V-power, as previous VWs were run on standard Shell.

After that i'm again quite serious about keeping the box just to have a car that actually performs better than the last one despite already supposedly having a 15PS advantage.

MH - have you tried setting the ACC to ECO for any length of time to see if it improves your mpg at all?  Mine is always set to ECO and it feels smoother to me when changing speed - and hence may possibly be a bit more efficient? Just a thought...

[monkeyhanger]

Skinnee D: By what do you mean ACC (there are so many acronyms, and that one has more than one designation)? I assume you mean adaptive cruise control. I don't use the cruise control, I don't consider cruise an economical way of driving and haven't been on a long trip (50+ miles one way in one stint) to even be tempted to set it.

If there is anything i've "done wrong" in the running of the car to get decent mpg, I suspect that it might be in the use of V-power Diesel. I have suspected since the last full tank that it's not as potent as regular Shell, but have stuck with it to give the car's consumption a baseline to see losses or gains made with the tdi-tuning box on.

My dad uses the cruise, and with the DSG (which he has), speed recovery following the car in front slowing down is epically slow in eco mode - it frustrated the hell out of him. He's averaging a true 48mpg (indicated 50/52) right now on regular diesel, which is 13% better than mine, when on paper his car (DSG) should be 10% thirstier like-for-like. He does have 6k miles on now and has seen modest gains. He also adds about 100mL Redex to every tank (it's cheap in Costco), not so much for the clean-up claims, but for the other additives that up the Cetane (Alkyl nitrates, aromatic compounds etc). He has been doing it for years now and hasn't stopped for the MK7. It didn't affect his MK5 170TDI's DPF operation at all.

[mcmaddy]

I never really turn the climate control off and when I do it doesn't make that much difference worth shooting about. the point with eco mode is not to blast around in it and expect increased mpg's. eco is perfect for town driving where you don't need any speed, then when you get out of town change to something else. maybe having yours permanently in sport mode is damaging your mpg's?