DTUK tuning boxes and/or remap economy - the truth?

[Gadget007]

Ok I have a MY15.5 VRS TDI with the DTUK box fitted.

 

I have kept record of every fillup with a long term average of 5.8l/100km

Recently I have had to take off the tuning box to get some warranty work done and had to do 8 consecutive tank fills with the car in standard trim (car well and truly run in at over 30,000km at that point)

over those 8 tank fills I got an average of 830.6km per tank full, since adding the box back and completed 5 tank fills i have an average of 866.8km per tank.  Over this time I haven changed the way i drive or where I drive (my wife uses the car also and has a heavy foot) so i can say that the use of the DTUK box has given me an improvement in economy (30km in 830 = 3.6%)

 

I generally fill up at the same place so i guess you can assume that the fuel type / quality should be the same.  Before I took the car back for the warranty work i was getting on average 860-900km per tank full.(my record was 945km with a mix of 75%highway and 25% urban driving).

 

Based on a 3.6% improvement and the records I have i guess that at 80,000 miles would get approx half the cost of the box back (based on what it cost for the unit in Aus dollars (including freight) and the average fuel price since i bought the car)

 

I didn't buy the box to get an improvement in economy i was chasing the few extra ponies, and i must say the driveability of the car is much improved and it can be tempting to use that extra power.

[Jono]

Yay for data!

[KenONeill]

I admire your faith in the accuracy of all fuel pumps on all forecourts

 

I tell you that's another minefield, apart from individual pump accuracy, the age of the fuel, water content, and here in Australia the temperature of the fuel served (expansion) is also a big factor.

Not to mention winter/summer fuels and I recently find out there are local rules here regarding petrol formulation to reduce 'evaporation rates'.

That is why they do all this stuff in controlled laboratories, and even then......

In the UK, fuel delivery is covered by "Weights and Measures" legislation, and the base requirement is that you must receive no less than the stated volume. This is enforced by random testing using (fairly large, usually 25l) calibrated vessels.

[SkodaVRS1963]

Just to clarify my car is remaped by Oscarli and does not have a tuning box fitted.

I didn't say I had 50mpg over the whole tank, only the 250miles between Sheffield and Edinburgh.

I ended up with 460 miles to that tank, assuming I used absolutely all the fuel in the tank (which I didn't as I had around 20-30 miles left on the range and the engine was still running :-), this is a fraction under 11 gallons) that equals 42MPG over the whole tank.

I reality there was probably 1/2 - 1 gallon left putting it mid 40's over the whole tank.

 

Something's wriggling.......can't seem to put my finger on it.

[SkodaVRS1963]

It wouldn't surprise me if it was showing 50mpg on the trip computer using the box - mine regularly shows that it's doing in the mid 60's whereas in reality it's only doing mid to high 50's when you calculate it properly.

 

My Focus (and my wife's Fiesta) frequently report 99.9 mpg on the trip computer.

 

But I wouldn't go onto a forum and post them as bible figures.

 

Sometimes common sense needs to take precedence over fanboy allegiance.

[GoneToBeemer]

My Focus (and my wife's Fiesta) frequently report 99.9 mpg on the trip computer.

But I wouldn't go onto a forum and post them as bible figures.

Sometimes common sense needs to take precedence over fanboy allegiance.

I was referring to average consumption, not instant.

Also, I wasn't quoting displayed figures as being gospel, quite the opposite in fact.

[SkodaVRS1963]

Just to clarify my car is remaped by Oscarli and does not have a tuning box fitted.

I didn't say I had 50mpg over the whole tank, only the 250miles between Sheffield and Edinburgh.

I ended up with 460 miles to that tank, assuming I used absolutely all the fuel in the tank (which I didn't as I had around 20-30 miles left on the range and the engine was still running :-), this is a fraction under 11 gallons) that equals 42MPG over the whole tank.

I reality there was probably 1/2 - 1 gallon left putting it mid 40's over the whole tank.

 

Hoist by your own petard, unfortunately.

 

Assuming a full to empty scenario, and using your figures, 460 miles out of a 51 litre tank = 41mpg.  That in itself is dubious in a 300bhp chipped engine.

 

But you reckon you got 50mpg on a 250 mile trip (22.7 litres).  That's entering Alice In Wonderland territory.

 

So the residue = 28.3 litres @ 33.7 mpg.

 

So, for whatever reason, your car did 33.7 mpg over 210 miles but then an astonishing 50mpg over 250 miles.

 

Please try harder.

Edited 20 September, 2016 by SkodaVRS1963

[xpower]

Hoist by your own petard, unfortunately.

So the residue = 28.3 litres @ 33.7 mpg.

So, for whatever reason, your car did 33.7 mpg over 210 miles but then an astonishing 50mpg over 250 miles.

Please try harder.

I was enjoying the 300bhp - but as it was 33.7 clearly not enjoying it enough

[Mallettsmallett]

Don't feed the troll.

 

Or his moobs.

[KenONeill]

My Focus (and my wife's Fiesta) frequently report 99.9 mpg on the trip computer.

 

But I wouldn't go onto a forum and post them as bible figures.

 

Sometimes common sense needs to take precedence over fanboy allegiance.

My record "best" is 675.3mpg. Of course, that was instantaneous data obtained whilst lifting off and going downhill!

[SkodaVRS1963]

Don't feed the troll.

 

Or his moobs.

Ah, the British way of labelling anyone "a troll" for daring to question anything posted that's obviously bizarre.

 

Not sure what "moobs" are though?

[peter312]

There are obviously a number of companies offering remaps to improve performance. Are there any who offer remaps to improve emissions?

[silver1011]

Whatever you do, do NOT do a Google image search for moobs.

 

[Orville]

There are obviously a number of companies offering remaps to improve performance. Are there any who offer remaps to improve emissions?

Surely nobody can beat VAG for emissions tweaking. They are infamous for it.

[Gerrycan]

Ah, the British way of labelling anyone "a troll" for daring to question anything posted that's obviously bizarre.

 

Not sure what "moobs" are though?

It's not that you questioned it, more the way you questioned it.

A guy takes his moderately tuned car, for a moderately paced run on an extended motorway journey and gets moderately good economy for that trip. Hardly bizarre.

Even @Xpower expressed surprise and I expect there were other non-obvious contributory factors.

Clement weather not requiring the air conditioner, possibly a slight tail wind or more likely he chose to drive moderately because of heavy traffic and that unintentional slip-streaming effect can assist by 5 mpg easily. Hard to say really but I believed the OBC figures at face value.

 

I couldn't understand your vitriol when he came back with some additional (and believable) information and you continued your attack with some very suspect maths of your own.

I remember how pleased you were with the reported consumption you achieved with your new Focus on the collection journey, seems little different to me.

 

The 'troll' epithet you earned is more accurate than the 'dual brand fanboy' you bestowed.

 

 

 

 

​

Edited 22 September, 2016 by Gerrycan

[KenONeill]

Ah, the British way of labelling anyone "a troll" for daring to question anything posted that's obviously bizarre.

 

Not sure what "moobs" are though?

"moob" - contraction of 'man boob' (contraction, colloquialism, mild vulgarism)

[themanwithnoaim]

"moob" - contraction of 'man boob' (contraction, colloquialism, mild vulgarism)

Usually grown instead of a pair of balls

[wiilydog]

On the topic of man moobs, does anyone know why God made man with nipples? Doesn't seem any purpose for them.

[KenONeill]

On the topic of man moobs, does anyone know why God made man with nipples? Doesn't seem any purpose for them.

We can't even see the topic from over here but all embryos are female for the first trimester, then sexually distinct characteristics start to develop.

[SkodaVRS1963]

It's not that you questioned it, more the way you questioned it.

A guy takes his moderately tuned car, for a moderately paced run on an extended motorway journey and gets moderately good economy for that trip. Hardly bizarre.

Even @Xpower expressed surprise and I expect there were other non-obvious contributory factors.

Clement weather not requiring the air conditioner, possibly a slight tail wind or more likely he chose to drive moderately because of heavy traffic and that unintentional slip-streaming effect can assist by 5 mpg easily. Hard to say really but I believed the OBC figures at face value.

 

I couldn't understand your vitriol when he came back with some additional (and believable) information and you continued your attack with some very suspect maths of your own.

I remember how pleased you were with the reported consumption you achieved with your new Focus on the collection journey, seems little different to me.

 

The 'troll' epithet you earned is more accurate than the 'dual brand fanboy' you bestowed.

 

 

 

 

​

220bhp tweaked to 300bhp is a moderate tweak?

 

I'd be careful posting stuff like that, DTUK certainly wouldn't want their expensive kit thus described.  And remember they are site sponsors.

 

50mpg out of a 300bhp petrol engine is moderate mpg?

 

Maybe things are different in Oz.

 

My maths was "suspect"?

 

I guess you aren't familiar with Excel........pump the OP's numbers in and voila.

[vRSAnt]

Is that Mpg using LPG ? or extreme and illegal hypermiling techniques ?

Max ( massaged official perfect conditions) figures are 45.6mpg for the 230 and everyone knows those figures are aspirational so probably at least 10-20% optomistic

 

There are just too many variables - Ability to reach perfect MPG is massively impacted by factors that to some degree are largely outside of peoples control (what journey you take to work, affect of wind or changes in speed / how many junctions and the like ).

Even factoring in hypermiling (some of which are illegal and plain stupid ). You can't do that all the time.

Maybe the one journey direction is downwind/ down incline and pays a more extreme economy price the first leg of the trip for instance ?

Its just meaningless......

 

With performance data  is often official printed underquoted stats at least, ( officially Fabia1vRS was 9sec ish to 60 which anyone with a BLT can tell you is well off, probably a second faster)......

and quarter mile measure times tend to be a good truth meter on performance.

With performance claims its easier for the bull**** meter to kick in when someone claims on performance stats like they burned off a Nissan 370Z or M3....!

We know as many of us own and use these cars

 

 MPG is so variable which is exactly why they must have those sites like fuelly for a proper long term balanced measurement. But short term I know in reality the cars indicating 40mpg or less more than it is pushing 50!

 

I got 70mpg indicated from the Fabia 1 vRS once from being a bit close to drafting a truck, just I don't go spouting it verbatim as the MPG.

I know the reality is at least 20mpg less day to day.

Trip usually indicates 50 going to 60 depending on driving on that car (with the Octavia slowing getting to its max of at least -10 the lower figure).

If you wanted economy, you got the wrong car with this. Great for speed though ! Wouldn't mind the 300 regardless of economy.

Edited 22 September, 2016 by vRSAnt

[Gerrycan]

220bhp tweaked to 300bhp is a moderate tweak?

 

I'd be careful posting stuff like that, DTUK certainly wouldn't want their expensive kit thus described.  And remember they are site sponsors.

 

50mpg out of a 300bhp petrol engine is moderate mpg?

 

Maybe things are different in Oz.

 

My maths was "suspect"?

 

I guess you aren't familiar with Excel........pump the OP's numbers in and voila.

Not my real interest but I'm led to believe from other posters that a Stage 1 tune gives less bhp increase than a stage 2 or 3, or upgrading a turbo as well, so "moderate" is a relative term to what can be achieved. 

 

You may refer to it as a 300bhp engine but it is still just  a modest 4 cylinder with just 2 litre capacity and we have already established that an ecu upgrade is capable of improving efficiency, particularly in cruise mode. It still only takes 20bhp (probably less) to propel an Octavia at circa 65mph speeds so why would the fuel burn efficiency be any less than a non-tuned engine? Still it does seem that 50mpg may be more remarkable for any vRS tsi engine (or your Focus) than it should be and honestly if that is the case then it is quite disappointing.

 

I don't doubt your ability to use a spreadsheet but I do doubt your ability to interpret the data that @xpower offered without bias.

He obviously did not remember the precise refill quantity but generously allowed a conservative tank full which is officially 50 litres (10.999 Imp gallons) and not the 51 litres you used in your calculations. If you add in the 20 odd miles left on range then actual overall consumption improves from 41.8 mpg to 43.63mpg.

The standard Octavia tank is actually closer to 55 litre capacity but the 'distance to empty' indicator rarely takes this extra capacity into account. In fact you once posted a complaint that you could not put more than 43 litres in on refill for your diesel following doe as a guide.

 

Sure it would have been nice if @xpower could have provided some supplementary data but I don't suppose that he thought he would be cross examined so closely when he reported some good results from one fairly long, conservatively driven journey.

 

One thing is for sure, I would not buy a high performance petrol engine car like the vRS tsi or the ST Focus because I would not use the performance it offered and I would not accept the lack of fuel efficiency at the speeds it is legal to drive at here.

It's nice that Skoda provide a choice for most tastes though. Sorry you were so unhappy with yours.

Edited 24 September, 2016 by Gerrycan

[Gerrycan]

Is that Mpg using LPG ? or extreme and illegal hypermiling techniques ?

Max ( massaged official perfect conditions) figures are 45.6mpg for the 230 and everyone knows those figures are aspirational so probably at least 10-20% optimistic

 

 

 

Not sure why you would think that using LPG would get better mileage? Here in Aus LPG is very cheap at the equivalent of 40p a litre but because of its low calorific value you have to use more of it than you would petrol. Still much cheaper driving than petrol or diesel though if your vehicle is converted to run it.

 

I'm not sure why you think the official figures are aspirational only. I can get close (or better) the official figures for my car in the right conditions without recourse to hypermiling or dangerous slipstreaming, but just using good traffic anticipation.

Today my wife and I travelled to a suburb 15km away to view some properties. Just after peak but still fairly heavy traffic and I achieved 60mpg for the outward journey, it was a bit better than I expected but it turned out I had a fairly strong tailwind. the consumption had dropped to 54mpg by the return journey but after completing the return it had recovered to 57mpg for the 35 km.

I do drive for economy and annoy my wife when I turn off the engine at traffic lights that I know have long cycle times. One set today took three cycles (so nearly 5 minutes of useless tickover time saved) to get through the junction.

My car is completely standard and pretty well matches a published fuel consumption/speed curve graph I have for a Golf 90kw tsi (my 103kw engine is supposed to be slightly more economical but is probably offset by the Golf's lower weight and drag).

My overall average is in my Fuelly at 45mpg, and that reflects the large number of really short local journey in my relatively low annual mileage, and I can't do much about that.

Edited 24 September, 2016 by Gerrycan

[SkodaVRS1963]

Not sure why you would think that using LPG would get better mileage? Here in Aus LPG is very cheap at the equivalent of 40p a litre but because of its low calorific value you have to use more of it than you would petrol. Still much cheaper driving than petrol or diesel though if your vehicle is converted to run it.

 

I'm not sure why you think the official figures are aspirational only. I can get close (or better) the official figures for my car in the right conditions without recourse to hypermiling or dangerous slipstreaming, but just using good traffic anticipation.

Today my wife and I travelled to a suburb 15km away to view some properties. Just after peak but still fairly heavy traffic and I achieved 60mpg for the outward journey, it was a bit better than I expected but it turned out I had a fairly strong tailwind. the consumption had dropped to 54mpg by the return journey but after completing the return it had recovered to 57mpg for the 35 km.

I do drive for economy and annoy my wife when I turn off the engine at traffic lights that I know have long cycle times. One set today took three cycles (so nearly 5 minutes of useless tickover time saved) to get through the junction.

My car is completely standard and pretty well matches a published fuel consumption/speed curve graph I have for a Golf 90kw tsi (my 103kw engine is supposed to be slightly more economical but is probably offset by the Golf's lower weight and drag).

My overall average is in my Fuelly at 45mpg, and that reflects the large number of really short local journey in my relatively low annual mileage, and I can't do much about that.

 

How many times in Adelaide do you have to remove ice from your windscreen?

 

In fact, do you know what ice is?

 

I think that might be part of the issue here; in the UK, we can be subject to sub-zero temperatures anytime between mid-October to mid-April.

 

That's six months of the year.

 

Has to affect fuel economy.

[Gromle]

I think that might be part of the issue here; in the UK, we can be subject to sub-zero temperatures anytime between mid-October to mid-April.

That's six months of the year.

Has to affect fuel economy.

Cold starts only has a significant impact on consumption on short trips. Once the engine is warm, I get the same mpg no matter the temperatur. 20 degrees or -20 degrees doesnt matter.

But short trips really kills the mpg, especially with a diesel.