DTUK and other tuners claim to increase your vehicle's economy.

 

We know a lot of this could be nonsense and naivety because the boxes fool the car into thinking it is injecting less fuel.

 

We also know people are really good at kidding themselves when they have bought something expensive that promises something, they convince themselves it is true.

 

We know that driving a car faster is *going* to use more fuel.

 

Realistically, a car is only driven at it's peak for a few % of its time.

 

 

Does anyone have reliable long term brim to brim data on economy before and after tinkering?

 

Does it pay for itself over 50000miles? or is that just wishful thinking?

How is setting the injector duty cycle at a specific load site to, say, 45% instead of 48% "fooling the car into doing something"?

I didn't buy my DTUK box for more economy, I bought it to get some more power out of the 2.0l diesel doneky in my car.

 

It does that pretty dam well, so I can guarantee you that I do not use less fuel....

 

Good quality fuel, optimal tyre pressures and a well serviced car carrying no more weight than needed will get you good MPG, not a remap or tuning box.

 

I think their rational behind the better MPG is the fact you have more power to get to your cruising speed quicker... :wonder:

I've tested mine, and it definitely gives better economy on a long motorway run (DTUK CRD3).

Calculated on a run from Newcastle to London and back vs. not having the box on, based on filling up / fuel used and not the trip computer.

However, the box will "fool" the computer into thinking the improvements are a lot better than they actually are.

On average I get around 30-40 miles more on a tank than I did before running the box.

I've had a few of my cars remapped and every one has shown a noticeable improvement in fuel economy.

How is setting the injector duty cycle at a specific load site to, say, 45% instead of 48% "fooling the car into doing something"?

It doesn't adjust the injector duty (on this application)

It reports low fuel pressure + manifold pressure so the ECU adjusts accordingly (turns them up to compensate)

Ps this weekend I did a trip from Sheffield to Edinburgh with ACC set o 68mph

I returned 50 mpg!!!!!!!!!

That's a vRS TSI stage 1 map + ITG filter with custom airbox plus brand new Goodyear Efficient grip tyres on the front.

I couldn't believe it, seriously good miles to that tank :-)

Best ever

Edited 17 September, 20169 yr by xpower

I couldn't believe it

 

You're not the only one.

 

300ps and 50mpg?

 

Hell, in one sentence you've just destroyed the entire diesel automotive industry.

 

:dull:

You're not the only one.

300ps and 50mpg?

Hell, in one sentence you've just destroyed the entire diesel automotive industry.

:dull:

300ps on a VAG engine = 28mpg

You can get more, possibly 50mpg hypermiling on a straight motorway. What's the point?

I've had 3 very different cars with this engine, & all performed between 25-35mpg over the lifetime of the car

300ps on a VAG engine = 28mpg

You can get more, possibly 50mpg hypermiling on a straight motorway. What's the point?

I've had 3 very different cars with this engine, & all performed between 25-35mpg over the lifetime of the car

 

Yeah it's awkward; clearly a dual-brand fanboy (possibly even a DTUK employee) but what can you say to them?

Yeah it's awkward; clearly a dual-brand fanboy (possibly even a DTUK employee) but what can you say to them?

Yep, just to qualify, I'm referring to the EA888 2.0 engine.

always frustrates me seeing a screenshot of 68.9mpg over 30miles. Great, show me 3000 miles!

Edited 17 September, 20169 yr by 999pooch

fanboy

Bingo!

Do I win anything?

My stock VRS TSI will return ~45mpg at a constant 65-70mph, so it is possible a tuning box (with slightly leaned-out fuel mix) can hit 50mpg at similar speeds on a clear motorway. Either that or maxidot reports slightly incorrecty due to fooled fueling.

My stock VRS TSI will return ~45mpg at a constant 65-70mph, so it is possible a tuning box (with slightly leaned-out fuel mix) can hit 50mpg at similar speeds on a clear motorway. Either that or maxidot reports slightly incorrecty due to fooled fueling.

Yeah that's the most likely explanation - as I've said, the DTUK box does improve economy, but it massively inflates that on the computer. Mine will frequently show 64/65 mpg on the display, but in reality that's more like 56 mpg in reality when calculated properly. Without the box, it would do around 50/51 mpg calculated.

Bingo!

Do I win anything?

No.

 

No sir, you do not.

There is enough evidence to suggest that ECU upgrades and tuning boxes do improve consumption although that is probably not why they were installed by the owners.

 

I was sceptical about some of the extraordinary claims for consumption improvement with the tuning boxes and many users have confirmed that the OBC readings were very optimistic, however most also confirm that there is real world consumption improvement and on face value I accept that.

Car manufacturers are burdened with meeting at least three performance targets, two are legal regarding consumption and emissions and the other is the customer expectation for adequate power/driveability. As we now know meeting all three targets (at an affordable price) is difficult, very difficult, whereas two out of the three is relatively easy.

ECU upgrades and tuning boxes are probably achieving two out of the three targets but I would be incredibly surprised if emission standards were not compromised in the process.

 

On an extended run a diesel will always achieve better consumption than an equivalent petrol because it has two natural advantages insofar as diesel has 10% higher calorific content and the diesel higher compression operation values. These advantages are compromised by DPF operation, and especially heavily in an unsuitable operating environment (multiple short urban runs).

 

It used to be a regular thing that a car manufacturer would highlight the economy of their new models with involvement in monitored record breaking distances achieved on a tank of fuel  in standard vehicles, mostly diesels and mostly with experts drivers.

Despite continued improvements in claimed consumption you do not see these economy runs now and I think it is because it would highlight the fact that modern diesels are not quite as economic as the older models which met lower emission standards. The official tests are so short as to avoid a DPF regen kicking in.

The last economy run I can remember was about a year ago by Peugeot in a petrol 308 on a closed circuit where they achieved (from memory) something like 99mpg at something like 57kph average to set some sort of class record. Note they did not try this with the diesel.

 

Those diesel drivers who are reporting that it is impossible to achieve better than 45mpg no matter how hard they try, then I just think their vehicle has got a major problem.

@SkodaVRS1963 has one such lemon, but having a dig at those that do get good economy is not going to make his lemon any less bitter.

 

One last point, there is a thread in the Superb 3 forum titled '96mpg !' http://www.briskoda.net/forums/topic/410541-961-mpg/

@Lasttriumph got that on one shortish trip but more impressively is getting 77mpg average over the first 2000 miles.

Just shows what a brand new diesel Superb, obviously running well and in the hands of a experienced practitioner of economic driving can achieve.

Edited 19 September, 20169 yr by Gerrycan

It doesn't adjust the injector duty (on this application)

It reports low fuel pressure + manifold pressure so the ECU adjusts accordingly (turns them up to compensate)

Ps this weekend I did a trip from Sheffield to Edinburgh with ACC set o 68mph

I returned 50 mpg!!!!!!!!!

That's a vRS TSI stage 1 map + ITG filter with custom airbox plus brand new Goodyear Efficient grip tyres on the front.

I couldn't believe it, seriously good miles to that tank :-)

Best ever

That's a comment on your specific device, rather than on remaps and/or interceptor boxes per se.

The only way of accurately calculating mpg is to record volume fulled and mileage between fillups and recording how much was used. I wouldn't rely on any other method. As much as the car calculation may well be based on measurements it can't calculate as accurately as the pump tells you.

Edited 19 September, 20169 yr by Mallettsmallett

There is enough evidence to suggest that ECU upgrades and tuning boxes do improve consumption although that is probably not why they were installed by the owners.

 

I was sceptical about some of the extraordinary claims for consumption improvement with the tuning boxes and many users have confirmed that the OBC readings were very optimistic, however most also confirm that there is real world consumption improvement and on face value I accept that.

Car manufacturers are burdened with meeting at least three performance targets, two are legal regarding consumption and emissions and the other is the customer expectation for adequate power/driveability. As we now know meeting all three targets (at an affordable price) is difficult, very difficult, whereas two out of the three is relatively easy.

ECU upgrades and tuning boxes are probably achieving two out of the three targets but I would be incredibly surprised if emission standards were not compromised in the process.

 

On an extended run a diesel will always achieve better consumption than an equivalent petrol because it has two natural advantages insofar as diesel has 10% higher calorific content and the diesel higher compression operation values. These advantages are compromised by DPF operation, and especially heavily in an unsuitable operating environment (multiple short urban runs).

 

It used to be a regular thing that a car manufacturer would highlight the economy of their new models with involvement in monitored record breaking distances achieved on a tank of fuel  in standard vehicles, mostly diesels and mostly with experts drivers.

Despite continued improvements in claimed consumption you do not see these economy runs now and I think it is because it would highlight the fact that modern diesels are not quite as economic as the older models which met lower emission standards. The official tests are so short as to avoid a DPF regen kicking in.

The last economy run I can remember was about a year ago by Peugeot in a petrol 308 on a closed circuit where they achieved (from memory) something like 99mpg at something like 57kph average to set some sort of class record. Note they did not try this with the diesel.

 

Those diesel drivers who are reporting that it is impossible to achieve better than 45mpg no matter how hard they try, then I just think their vehicle has got a major problem.

@SkodaVRS1963 has one such lemon, but having a dig at those that do get good economy is not going to make his lemon any less bitter.

 

One last point, there is a thread in the Superb 3 forum titled '96mpg !' http://www.briskoda.net/forums/topic/410541-961-mpg/

@Lasttriumph got that on one shortish trip but more impressively is getting 77mpg average over the first 2000 miles.

Just shows what a brand new diesel Superb, obviously running well and in the hands of a experienced practitioner of economic driving can achieve.

 

You're labouring under a misapprehension.

 

I'm fully aware that my VRS was a lemon but what I won't listen to is owners of petrol engines claiming they're getting 50mpg out of a chipped 300bhp.

 

Everyone with a working brain cell knows DTUK would be promoting this to the max if it were true (and why not, I would if I manufactured such a super-whizzy device?)

You're labouring under a misapprehension.

I'm fully aware that my VRS was a lemon but what I won't listen to is owners of petrol engines claiming they're getting 50mpg out of a chipped 300bhp.

Everyone with a working brain cell knows DTUK would be promoting this to the max if it were true (and why not, I would if I manufactured such a super-whizzy device?)

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.

Are MPG claim figures becoming a bit like claims of fertility in the bedroom? Easier said than proven

 

Kind of irrelevant also, all cars having a drinking problem and eventually you are going to find yourself at the expensive petrol station so no point trying to be smug either which way. I think the only real concern is whether you are getting the expected mpg for your model.

 

IMO I'd be happy with the 300hp.

If its not 50mpg ( which I'd find extremely hard to believe anyway for the 220) then so be it

If its at all any improvement over the standard economy ( which for me was 40+ ish mpg (MAX) before last plug change then I'd be fairly happy), but I'd find 125% improvement a bit of a stretch of the imagination until proven.

Edited 19 September, 20169 yr by vRSAnt

On total 6500 miles i get 36,6 MPG in my rs230. This is from fillups. And not the cars computer. Standard car. Bet its not much better in a tuned version.

Just my opinion.

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.

The only way of accurately calculating mpg is to record volume fulled and mileage between fillups and recording how much was used. I wouldn't rely on any other method. As much as the car calculation may well be based on measurements it can't calculate as accurately as the pump tells you.

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......

You're labouring under a misapprehension.

 

I'm fully aware that my VRS was a lemon but what I won't listen to is owners of petrol engines claiming they're getting 50mpg out of a chipped 300bhp.

 

Everyone with a working brain cell knows DTUK would be promoting this to the max if it were true (and why not, I would if I manufactured such a super-whizzy device?)

 

Just one working brain cell? Explains a lot

Are MPG claim figures becoming a bit like claims of fertility in the bedroom? Easier said than proven

 

Kind of irrelevant also, all cars having a drinking problem and eventually you are going to find yourself at the expensive petrol station so no point trying to be smug either which way. I think the only real concern is whether you are getting the expected mpg for your model.

 

IMO I'd be happy with the 300hp.

If its not 50mpg ( which I'd find extremely hard to believe anyway for the 220) then so be it

If its at all any improvement over the standard economy ( which for me was 40+ ish mpg (MAX) before last plug change then I'd be fairly happy), but I'd find 125% improvement a bit of a stretch of the imagination until proven.

 

It's a forum, mpg claims are no worse than some acceleration, top speed, exotics burned off at traffic lights claimed by others.

Not seen any bedroom statistics here yet though, are you confusing your forums?

 

I'd agree that a 25% improvement (125% needs a long downhill) is more possible with a change of driving habits than just a change of spark plugs

The 2009 Darwin to Adelaide 'Green Challenge' was controversially won by a Holden Special Vehicle (HSV) 6.2 litre V8 petrol ute because the rules stipulated the greatest improvement on the official combined consumption figure.

The HSV official combined was 15.1L/100 and they achieved 7.7L/100 which I think was about 48% improvement. Diesel minis and fiestas achieved about 3.2L/100 but only 15% improvement.