So, I managed to blag the use of one of these boxes for a try-out.

Particularly as our friend Sinny has had one and liked it, but can't get the power down to the tarmac! Not many Autobahns in rural Shropshire though, in fact, there aren't that many dual carriageways

Quite a difference it made too - I'd say it has made my Dobby the car Fiat should have built in the first place!

Firstly, the boring facts. I have been doing a regular daily run for the past couple of weeks or so. Main roads to country lanes with some peak time traffic congestion. 28 miles each way. Stop/Start disabled. Varied weather - rain, sunshine (mmmm Aircon!)

Nothing overly scientific, but I brimmed the tank and ran it down to a quarter full. Average fuel consumption 43.7mpg, average speed 32mph according to the trip computer - fuel readout pretty close to the 43.7 measured surprisingly.
Connected the box up (at the filling station, it only takes a minute to swap plugs over). Another few hundred miles of what constitutes my Dobby running at the moment until a quarter full. Surprise, surprise, the fuel readout of 47.9mpg, backed up by brimming the tank again. Average speed was 32mph as well.

So those are the bald figures, but they don't tell the whole story, and for me, I accept the almost 44mpg, so almost 49mpg is a bonus, but nothing for me to get excited about.

I set the box up for the "mildest" setting, concentrating on low and mid range performance. I rarely rev the car over 3000rpm, and in deference to my DMF, I tend to keep the engine spinning over 1800rpm. I have my moments, but I tend to drive reasonably steadily, although not for economy, and I ignore the gear change prompts.

The car, as standard is utterly gutless under 2000rpm, then it starts to produce some go. This is very tedious on the lanes, having to constantly change gear at every corner. The tuning box has transformed this part of the rev range. I can now accelerate cleanly from my chosen lower limit of 1800rpm, and it's quite happy at 1500rpm, even in 6th. The first run home after removing the box was a revelation, I hadn't realised just how much work I was putting in to driving the car on the lanes. The tuning box made the engine so much nicer to drive, with plenty of torque within my rev range. It certainly felt significantly faster accelerating, I could tell the turbo was spooling up nicely at 2000rpm and above.

I did notice that I had a flat spot at 1500rpm with the box on - but when I took the box off, the flat spot was still there, just not as pronounced, so it was something that I'd missed previously. The engine doesn't sound any different, and there is no extra smoke, even under hard acceleration - but there shouldn't be as my car has a DPF.

So now I am in a quandary. I want a tuning box - this one set up as it was suits my Dobby driving well. After next week, I'm not doing the 28 mile runs any more - or at least not regularly, but I am missing the box already. Can I justify the cost of the box, then the hassle of Admiral insurance wanting an arm and a leg extra as I've modified the car.....

Food for thought.

Mike

Mate, I swear by mine. Like you say - it's a different motor. Now I've learned to put the power down cleanly I hardly ever spin the clutch, but it's a pootle up to about 1500, then progressively stronger, then just after 3000 it really kicks in like a big slab of power.

Couple of months ago I did a 1200Km run to France and back, and I swear, the rev counter never went over 2K all the way there and back, and I just sat at just under 100KPH and it sipped juice. Can't remember the figures now, but the fuel light came on after 1100 Km - I probably would have made it home but I bottled it and filled up again.

Like I said, I paid peanuts for mine second hand on flea bay - just keep an eye out - but I think new they're only circa 70€??

Cheers

Sinny

Not quite sure what are the long term affects of using a plug in box? Is it not just fooling sensors about the engine & increasing fuel pressure to the rail, like compensating for cold conditions etc? I would of thought that an ECU remap would be the way to go? But I dare say some considerable costs would be incurred.

Probably so.
To get an ECU remap done properly, you'd need a rolling road to tune it to the engine.
Not worth it in my view
The box didn't cause any smoke (that I could see) but the improvement in driveability was huge and the improvement in fuel consumption would seem to suggest that it wasn't just overfuelling.

Mike

a custom remap is by far better, the doblo can be remapped and the results are well worth it, mine was mapped on the dyno and on the road so it was put in real worth situations, it wasnt done by simulation which is where most remappers these days do (glorified downloaders and uploaders I would say) hence why mine doesnt chuck out any black smoke!

Its ok if you're not do 30,000 ayear seems to clog up EGR tried on both my 1.3 mjet 1st EMLegr had to be cleaned , second developed a miss at low revs, removed the box and afterffew weeks sorted itself out. It did run better for awhile with the box on.