Diesel tuning chips

[Piff]

I filled up the ML270CDi for the first time today. 340 miles, of which about half was a single dual carriageway journey with cruise control on at about 70mph.

Reasonably pleased with 28.5mpg overall.

I will be doing about 15,000 miles a year, about half on restricted A road (50mph & 30mph through villages and the other half on country B roads.

Local independant is an agent for DPT (www.dieselpowertuning.co.uk) and I'm wondering if it is worth considering:

I've got 1 year MB warranty - would this be invalidated?
I've got mobilolife - would this be invalidated?
DPT claim 5 to 10% fuel economy improvement - is this realistic? (in my case worth £130 to £260 per year)
DPT claim up to 30% more power & torque - is this in addition to improved fuel economy?
DPT claim to be MB approced in the Netherlands.
Presumably insurance company need to be notified - I guess they may decline/terminate cover or just charge more - any one know how much more?

Has anyone got real-world experience of these type of units & what are their opinions?

Thanks

 

[Ted]

In last weeks Auto Express

 

[mw_C32]

Dont believe the hype.

I have had several tuning chip type things (plug and play only) installed in all my diesel cars and I have to admit to a very nice increase in power from them all and of course a substantial increase in MPG as stated in the on board trip computer.

Eg.

Touareg 2.5 tdi 173bhp normal 25mpg with chip 34mpg
Astra 1.9CDti 150bhp normal 48mpg with chip 59mpg
Peugeot Boxer 100bhp normal 31mpg with chip 39mpg

All good you might think until its fill up time. I got really confused when I needed to fill up when the car/van had actuall done less miles than without the chip so I did a fill to fill mpg and whilst all the on board trip computers stated I had done more mpg in reality it was 2-5mpg less than normal.

Maybe I drive a little quicker with the chip in as there is certainly and without doubt a marked improvement in performance but I did try to drive like I had an egg under my right foot and I could not match the mpg I got without the chip installed.

I still have one in my Boxer as I'm happy to get a little more performance out of it.

Only my observations mind and I'm sure others will differ.

M.

 

[raymont]

Suspect confusion is because the car computer measures fuel consumption by by counting fuel 'pulses' which it assumes deliver a certain amount of fuel. The chip / box probabaly puts more fuel into each 'pulse'.

 

[paul_f]

If the diesel chips are all working by using the rail pressure sensor, then the MPG increase on dashboard can't be used.

By modifying the signal from the sensor, you are increasing the amount of fuel injected, but the ECM will be calculating the amount of fuel injected from what it thinks the pressure is

 

[rf065]

Just to muddy the waters a bit more,
on a recent trip 550 mile trip each way, I measured the MPG with the trip computer & the brim to brim method. Without any tuning chip fitted, the brim to brim method showed the car was getting 2 or 3 MPG more than the trip computer was stating.

Russ

 

[Mactech]

My own experience suggests:
• Most add on boxes work by increasing the fuel rail pressure.
• Increased rail pressure means more fuel per injection
• This will give a performance increase.
• More torque, when used to allow earlier gearshift points can increase economy.
• Increased fuel rail pressure will skew the fuel meter readings as the ECU calculation is written for a specific rail pressure.
• If the power has risen by a percentage, then the rail pressure will have risen by some proportion of that and likewise the inaccuracy of the fuel meter.
• I have direct knowledge of three of the V6 diesels in standard trim and all the fuel meters have been accurate to within 2% checking by tank to tank fills. This is as good as we can reasonably expect production tolerance parts to be.
• Re-mapping the ECU overcomes the fuel meter accuracy problems of the external boxes as the dwell of the injection pulses is normally altered, not the pressure.
• The concerns will warranty and insurance are still valid

I hope this experience is some help.

 

[mercmanuk]

i fitted a dpt chip to my fiat doblo 1.3 multijet diesel,the differance was amazing it is faster than the 1.9td from standstill and through the gears also on overtaking on the motorway.i seem to be getting about 5mpg more due to the increased torque and not needing to rev as high

i highly recommend them

 

[Rory]

Suspect confusion is because the car computer measures fuel consumption by by counting fuel 'pulses' which it assumes deliver a certain amount of fuel. The chip / box probabaly puts more fuel into each 'pulse'.

I was astonished to read that report and see that they used the cars computer to measure the fuel consumption.

I thought magazine road testers always used specialised equipment for measurements so they should be well aware the computer can't be relied upon.

 

[mw_C32]

I was astonished to read that report and see that they used the cars computer to measure the fuel consumption.

I thought magazine road testers always used specialised equipment for measurements so they should be well aware the computer can't be relied upon.

My thoughts exactly.

///M

 

[paul_f]

I think magazine testers rarely do stuff like that nowadays, it costs too much money and it wouldn't give the results they wanted....
I wonder if that company advertise in that magazine...

 

[crockers]

I think magazine testers rarely do stuff like that nowadays, it costs too much money and it wouldn't give the results they wanted....
I wonder if that company advertise in that magazine...

Paul ... change your avatar to Mr Cynical....lol..

 

[tuikku]

.
Some tuning-boxes increase the rail pressure, some lengthen the injection time.
Both cheats.
The one, which makes injectors spray longer, is better.
Increasing rail pressure is risky.
With both boxes, program calculates the injection-timing wrong.
(I mean also timing, not only time)


Remapping is better way.
In almost every MB cdi´s, there is enough fuelling loaded in program to get the power and torque, that stock engine can give.
To have some kind of effect, and more, that tuning-boxes gives, only needs to realise the limiters, tune EGR, a bit more boost (~0,1bar), and sometimes very tiny change to smokemap.
After that, everything works like before.
Program knows the real amount of fuelling and calculates everything right.