General: Wow... I'm impressed

[petrolhead69]

They can improve mpg slightly if you use the extra torque to shortshift, but if you use the extra power to go faster then mpg will be worse. The obc overreading isn't a con, just an inevitable side effect of the way tuningboxes work by increasing fuel delivery without the ecu knowing.

[Zoidy]

Hi all,

I recently bought a professional tuning box from a company near me in Surrey with the promise it would increase torque and mpg efficiency.

I put it to the test on a 1500 mile round trip to Milan and I have to say, the extra power is great and its only set on the 3rd setting out of 10. But ... the computer readout of the mpg is completely screwed up whilst the box is being used.

The other issue is the mpg. It's actually much less than the car does without the box. I filled up 7 times from home, throughout the journey and on my return to the UK and the average mpg I got was only 30mpg.

I just did a 50 mile return trip down the M25 without the box connected and (filling up before I left and then when I came back) I got 44mpg.

So, I definately do not recommend tuning boxes if you want both extra power and efficiency. You also will no longer be able to rely on the cars miles left in tank calculation etc.

I have an MY10 by the way. 185ps.

[chb]

Ask yourself this. If car makers could safely tune the car to get extra mpg and extra power, without causing damage then would they not do this at the factory?

Tuning boxes are a con for the gullible.

[AB-UK]

"I have an MY10 by the way. 185ps."
So do I, but there's no way I get within 10mpg of this.
I am not lead-footed, so how on Earth did you manage 44mpg?

[G1zmo]

I have to say I can't believe the mile per gallon figures I see some lucky folk on here getting. 44mpg in my dreams. I have a 2010 MY, 185bhp, always Volvo serviced so presumably has latest software etc. I never see more than 28 on the readout and believe me I am lightfooted so it's not getting ragged around. When towing, albeit a fairly big six berth van, the mpg is around 23/24.

I'd pop angry hornets in my undies to get 44mpg ..............probably!

[Ninja59]

Originally Posted by chb

Ask yourself this. If car makers could safely tune the car to get extra mpg and extra power, without causing damage then would they not do this at the factory?

Tuning boxes are a con for the gullible.

All matter of reasons...

take for instance the recent one from Chris Harris http://www.youtube.com/watch?v=2KfMY96v_Gc

a really interesting video displaying that some manufacturers do it to ensure that one engine does not get to close to the top of the line one that commands a greater amount of money in this case the S4 v RS4. Another instance of this was the previous Porsche Cayman for instance every figure was exactly middle of the Boxster and it's bigger brother the 911. Remapped the Cayman was easily level with some 911's, simply Porsche not wanting their mid range car to level pegging the 911 as that would just be stupid and defeat the object of the 911 being there, which of course was more expensive.

Another one is simply purely in regards to safety and not overstretching engines as a whole, and on the whole many produce more than the quoted book figures in many instances.

Another potential issue with using book figures is the very fact if you drive a car normally from new using the rev range properly then there is an amount of evidence showing that in the long run these cars produce more power than those that have been like a princess should I say at the start of their lives. A friends A5 3.0 TDI Vs S5 was close and it was producing 300, the book was something like 270 from memory now some of it will be down to it potentially being more powerful than the book figures but some of it was proven against other A5's to be well up on their figures by 10/15 extra ponies.

[Shadeyman]

Engines are tuned to the manufacturer's recommendations to ensure a car runs as expected in all environments. This requires the engines to be "de-tuned" to give better results over a wider range of environments. Fine tuning via a remap for example takes advantage of the "manufacturer de-tune" and gives very good results in most cases. Good results can sometimes be had from tuning boxes depending upon how the box works. Most of them just fool the ECU into producing more power so the MPG displayed is usually wrong unlike the a remap which are usually quite accurate.

[Zoidy]

Originally Posted by AB-UK

"I have an MY10 by the way. 185ps."
So do I, but there's no way I get within 10mpg of this.
I am not lead-footed, so how on Earth did you manage 44mpg?

This was a 5 mile A road, 16 mile motorway, 4 mile A road journey. Motorway was an 80mph cruise. Same journey back. I inputted the mileage and fuel intake from the pump into two different Android apps and got the 44mpg figure.

If I was to do a month of mainly local roads with one trip on the motorway I'd expect to get around 27 mpg average over that time.

[Funky Diver]

Originally Posted by chb

Tuning boxes are a con for the gullible.

Precisely as Ninja has said...

I quite happily got an extra 15mpg AND increased performance measured on a rolling road from a 1.8 Scirocco (Mk2) using electronic ignition over points, and then to a different "tuning" box (I added something to it) and increased it again. Same engine, slightly different characteristics.

I presume you have empirical proof that it doesn't work? If so, I'd love to see it.

I can't comment on the MPG for sure, as we haven't measured it... however the wife is making the £50 she puts in last longer somehow without really changing her driving habit... and the car IS much more lively with the box turned on, both advancing and retarding throttle. So it stands to reason that actually.. so it is making a positive impression on the performance of the engine.

The wife noticed the car behaviour change, she didn't even know I'd put it on for the first week... until I told her.

[petrolhead69]

That is because the electronic ignition conversion allows far more accurate timing control which has a huge effect on performance and economy. Lumenition? The majority of diesel tuning boxes crudely adjust 1 parameter out of spec. The end result feels good, but its doing damage to the fuel system caused by overpressure and the extra performance is achieved by squeezing in extra fuel the ecu doesn't know about. A tuning box is not a remap. If your tuning box only plugs in to the fuel pressure sensor and nothing else Its like doing steroids. Better performance short term but damaging in the long run.