So, I found myself bored in a meeting at work this morning, and started thinking about tuning boxes.

for £82 I could get this:http://www.ebay.co.uk/itm/Ford-Mondeo-TDCi-Diesel-Tuning-Box-Chip-/231121945273?ssPageName=ADME:X:eRTM:GB:1123

Had it confirmed that it is definately going to do my car, but I am lacking one thing which is stopping me hitting buy! I cant find anyone on the net who has said what the MPG improvement was realistically. I came across one person who said their berlingo gained an extra 100 miles in fuel, but thats all I got!

If I knew what the realistic economy improvement was, I would happily buy it, knowing that I might need to offset the loss for say 1 month, but then after that I am in nothing but profit! but I just cant find these answers!

Has anybody used a box similar to the above on their Ford (preferably mondeo) and can you advise if you got any decent fuel returns.

My current maths is this: so if anyone can correct me... :)

If I do 650 miles on a £90 tank, that works out as 45 MPG.

If I break that down (by diving the Miles Per Gallon, by 4.546 - the number of litres in a gallon) I get a result of 9.89 Miles per litre.

If I now divide that by the approximate price of 143p (the cost of one litre of fuel) that works out at approximately 14.44 pence per mile.

Now If I take an average of 100 miles gained from a tuning box, that means every tank of fuel would save me £14.44p. On that basis, it would take me circa 5 fillups to pay for the box, and anything after that is a saving :), that would probably mean that after Christmas I would be quids in :D presuming I actually get 100 miles extra per tank!

As far as I can tell that is a first generation box.

The second generation boxes on their website cost more but are far more up to date and give better results.

I fitted a second gen box from them to my mates mk2 Focus and he is quite impressed with the results.

Yeah, I would love to afford a second gen (or remap for that matter) but living on a budget, I am trying to find where best to invest to get the best return.

The claims are still the same as the second gen box, I guess the question is if its really reflective of that. If I was to get enough out of it that I would start saving money say around christmas and it gives me the power when I need it, but moreso helps to boost the MPG thats the main thing I am after! I struggle at the moment to justify the money on the first gen, let alone the second :p

What I might do is wait until my insurance pays out, then maybe get one after I have got the engine a terraclean, then I am sure I would get much more money back on the day to day running!

Indeed a good engine clean plus a box will help.

A good air filter (K&N, GreenCotton, Pipercross) will help the engine to breathe in better and add a bit of bang for your bucks.

tis true, I was contemplating a K&N, but then as they have their own insurance modification, I thought perhaps someone elses name who isnt on the modification list as a chargeable item might do the job :)

I will see how many bucks I have left at the end of the month, but given that work is paying for me a swanky hotel and a day away from the kids with the Mrs, I suspect she will want my money!