Fuel Saving Remaps

[turbopete]

well my car has none of the electric gizmos, no fuel computer etc, and id risk being a guinea pig and repeat the same run i did, under the same conditions, as near as is possible in the real world, or even on a track, run for say an hour as is, then re map then run again for an hour/same no of laps at same speeds etc to see what difference it made! except i cant afford a remap at the moment as i have more pressing issues with my car!

not saying i believe in any sort of voodoo, but id be willing to be a test bed, if finances allowed. just to settle the argument 1 way or the other!

 

[roadhog]

You'd have to get yours started first Pete..... :lol:

 

[jberks]

Thus, why would a computer, which is performing the dosing, not know how much fuel it injected in dose A and dose B? Is it a Freudian guess? No, its almost exacting science.

So, how can a trip computer mis-read? Perhaps it looks at the stars, decides its a Libra and gives a balanced guess........??

If the re-mapper tells the ECU, by injector coding, that the injector doses less or more than it actually does, then yes, it can misread, but why would a re-mapper need to do this, given they can control the time the injector is open?

Fuel computer accuracy is a tricky one and I'm quite happy to admit I don't know enough for a definite conclusion, but I would say that I suspect it depends on the sophistication of the system. I doubt all ECU data is read by the trip. Probably just the bare minimum needed.

The number and length of injection pulses plus pressure all determine the fuel used. I would imagine that all of these factors can be adjusted by a remapper but whether they are accounted for by the fuel computer is a different matter. What I keep coming down to is that the fuel computer is always pretty innacurate on a normal standard car. This innacuracy leads me to suspect that the speed and complexity of factors taken into account by the ECU, which theoretically knows to the last drop how much fuel has been consumed, are far more detailed than those used by the trip computer. So, for example, the fuel computer may count injector pulses but it may be working on preset average pulse time and pressure - fine for average use and close enough over a tank full, so adjust either of these and the fuel computer won't allow for it.

As I said earlier, it is possible - as with the 240 and 320 engines where the 320 is better suited and so provides more performance for the same fuel used and some of this improvement could be replicated by a remap on a cdi but I would imagine that if this were so, smaller engines would show improvements whereas larger stuff like a 270/320 which already have excess power, wouldn't.

I'd also say that some confusion when I think about it, come down to the difference between tuning boxes and a remap. Whilst I suspect it is 'possible' for a remap to be taken into account by a fuel computer, I'd be very suprised if the same were true for a tuning box, yet both make the same claims.

 

[jberks]

Just read Alexander's post and he perfectly hits the nail on the head. Energy in - efficency loss - energy out. You can reduce some inneficiencies as 90% of them will be drive train, wind and tyres, the amount that will effect is minimal. Yes it is perfectly true that lowereing torque peak down the rev range should allow earlier changes but once up to speed, I'm in 5th anyway. The revs are what they are and the fuel added to maintain the speed, or increase it will be unchanged. The 270 is grunty enough to run permanently below 2200rpm so earlier changes are unlikely aside from in traffic.

Not negative, just scientific - I'd still like a remap .....

 

[sr-performancelive..]

Hiya mate, take it you've never had a remap? or have you been in a car that has had one?
I'm only asking because it is like night and day when remapped.
I remapped a Transit for Allgears in worksop and he text me later when he had time to drive it and to say he was amazed is an understatement and he wanted to know why ford didn't sell it like that..His words.
You do get a 7 day money back guarantee if you want to have a remap??? he he.

 

[turbopete]

You'd have to get yours started first Pete..... :lol:

true. not a problem. as long as i dont need a fuel stop when the engine is hot! then id have to wait 2 hours or so!

 

[turbopete]

Just read Alexander's post and he perfectly hits the nail on the head. Energy in - efficency loss - energy out. You can reduce some inneficiencies as 90% of them will be drive train, wind and tyres, the amount that will effect is minimal. Yes it is perfectly true that lowereing torque peak down the rev range should allow earlier changes but once up to speed, I'm in 5th anyway. The revs are what they are and the fuel added to maintain the speed, or increase it will be unchanged. The 270 is grunty enough to run permanently below 2200rpm so earlier changes are unlikely aside from in traffic.

Not negative, just scientific - I'd still like a remap .....

true, but i believe the parameters on the engine can be set up to reduce the amount of fuel injected at cruising speed. this is probably done (i dont know as ive never learned how to remap engines etc) by a very slightincrease in the turbo boost pressure. it would be below max boost by a long way still, obviously

 

[psmart]

here is a question, a vehicle produces a certain amount of power (eg that needed to cruise at 70mph in car X) at a certain rate of fuel consumption, all steady state assumptions here................anyone know where i am going next?

how can we suddenly use 15% less fuel to make the same power? same engine rpm, same bhp produced, same mechanical losses. the conclusion is that it is only possible if the engine was not combusting all of its fuel in the first instance. with a diesel, as many here will know, that means lots of black smoke. 15% overfuelling is a lot and the smoke produced would be chronic.

there is no such thing as a free lunch, think about it. extra power from a re-map is a verified and believable claim, but 15% fuel saving? how? throttle back the fuel by 15% and you loose 15% power.

fuel savings may be possible by optimising injection firing point, tweaking egr function, turbo boost, deceleration shut off and gbox changes, maybe even the shut off flaps, but never by that 15%.

How many of us jump into a car going 70mph and jump out? Difference between theory and actual is the real world, we all have to wake up, jump in a cold car, stay in jams, cruise etc. The theory is sound, but the application isnt. The remappers arent claiming fuel savings at <x>mph on a flat road with no wind, their claiming across board, average driving.

Then comes items that we dont need, like EGR you mentioned, why recirculate spent gases, depleted of oxygen and containing CO/CO2 amongst others which kill combustion, perhaps on the off chance there is a bit of unburnt fuel? The manufacturer has to worry about pollution, the remapper doesnt. Ive heard of no mention of pollutant testing after a remap, all the car has to do is pass the MOT!

i don't believe in horroscopes, magic or religion either btw. i hear there is a million dollar prize for any proof of supernatural phoenomena of any kind, demonstrated under SCIENTIFIC CONDITIONS. the prize is yet to be claimed, though many believe in all the things above.................

In China, many have a very positive outlook towards say Religion, to believe in no religion, your certain of where your going, but to believe in all religions, your in with a chance. A closed mind means your stuck with what youve learnt right or wrong, an open mind allows you to progress and better yourself.

As Steve has done, put his money and business on the line, you cant ask for more than that, other than everyone on here to have an open and honest mind. Colechelle is testing out on his C200, but he is a mechanic, so you also need a person of no opinion and a economical driver (would spot the improvements more than a heavy footer) and someone who believes unequivocally in the claims. Then all can report back.

 

[Alex Crow]

hellp psmart

although i used a steady state example for simplicity, the same points would work for transient states too, it seems the gearbox ecu and gearchange points are not changed from what sr performance has said btw.

egr is used to do much more than clean up emissions - it hardly recirculates any significant percentage of exhaust gas anyway - its combination of products of combustion and part combustion are found to aid the combustion of very rare (ie weak) intake mixtures. a diesel after all has no significant intake throttling to meter air intake at idling and very low torques, exactly where egr is used, mainly to improve combustion. i can believe that a remap could improve combined everyday economy figures, but i will eat my hat if it reaches the dizzy heights of 15%. the remap chappie said early on that they guarantee at least 15% fuel saving, when sam unit volunteered it suddenly dropped to '8 to 15%' :roll:

my religious dis-beliefs are a weakness, i usually describe myself as an agnostic - ie i keep my mind open, which being scientifically minded i of course do. however i have yet to see one jot of evidence to suggest truth in any mainstream religeous belief, but the reasons why people do believe are glaringly obvious. after all, if god didn't exist we would have to invent him..................sorry if this seems a little off topic, but we really are drifting into the philosophy of belief vs proof, and i will always believe the proof, when scientifically proven.

 

[roadhog]

But you are wrong about the reviews by expert magazines. Not one has ever claimed that a simple chip will improve your fuel economy by 15%. Find me one and I'll give £100 to charity. And you can choose the charity.

http://www.autoexpress.co.uk/news/autoexpressnews/229392/the_mpg_boosters.html

Dear Mr hawk, I've just read back a bit and I still think this qualifies for your charitable donation. Give or take 1%. :lol:

 

[sr-performancelive..]

And I'm sure I put an av 15%

 

[whitenemesis]

And I'm sure I put an av 15%

Wouldn't that be even more ambitious? There would need to be some savings of well over the 15% to give you that average!

But nicely impossible to verify with such a small sample.....

 

[hawk20]

http://www.autoexpress.co.uk/news/autoexpressnews/229392/the_mpg_boosters.html

Dear Mr hawk, I've just read back a bit and I still think this qualifies for your charitable donation. Give or take 1%. :lol:

No sadly it makes the terribly simple and naive mistake that Jberks has referred to in many posts. It assumes that the computer read-out in the instrument binnacle is correct and as many have pointed out in the past (best put IMO by Jberks) the remap alters the accuracy of that read-out. A very shoddy, unscientific piece of work IMO. Really an 'advertorial' done mainly to drum up advertising revenue.

BTW asking one owner to test a chip and draw conclusions for us all is equally naive and unscientific. One owner, with one type of car, in the condition it is in, on Britain's roads where every journey is different, is not a test from which firm conclusions for the many can be drawn.

Many things that are sold in Britain and in mainland Europe have to be properly tested before sale and before making idiotic claims. Why don't chip sellers get proper independent tests done on their claims? Pity they aren't regulated and made to do so. Fortunately car makers have to give us tested info on CO2 and mpg.

Chips can increase power -we probably all accept that and rolling road evidence and proper performance testing has been done by magazines to prove that. After all, it is always possible to bung in more fuel and get more grunt at a cost. And Brabus, of course, sell tested, guaranteed chips specially for MB cars.

But even with the MB approved chips, the warranty is reduced to 60k miles so presumably there is extra wear and tear from the higher performance -as we would expect.

Non approved chips from the many small suppliers make the 3 year warrnaty invalid and no chance of goodwill contributions in year 4 either. So IMO only older cars should consider non MB approved chips -unless happy to lose the warranty etc.

Then as AutoExpress point out most insurance companies will load your premium or even refuse insurance if you modify. Although chip makers often claim there are no insurance problems, phone your insurance comany and they will almost certainly say that any mods have to be declared. Have an accident and if any mods are detected they can refuse to pay out. Could be expensive. So always notify your insurance comapny.

Detuning the engine can give more mpg. See the various versions of the 2 litre diesel engine for the A class, where the least powerful gives the best mpg. But few of us want less power even for a bit better fuel economy, do we? Claims to offer more power and better fuel economy are best taken with large pinches of salt UNLESS backed by rigorous scientific testing by independent bodies on realistically large samples. IMO.

 

[roadhog]

Talk about moving goal posts.

You asked for one review by a magazine of a chip increasing mpg and I gave you an example. There was no mention in your original post of scientific this or that so why now? Then, when it suits you, you cite the very same magazine article to back up your opinion on things like insurance. Which way would you like it? I'm beginning to think you're not as charitable as you would like us to think.

 

[SQ_W211]

Some people are hard to please I guess

 

[Xtractorfan]

I think i have to agree with hawk here on this one ....I know sod all about chipping either .

 

[hawk20]

Why not get What Car or Autocar or Which to do a proper scientific test and then even I will be convinced. Till then 1000 bits of anecdotal evidence prove little. Conditions vary, drivers vary, traffic varies, temperature varies, aircon on, aircon off etc etc.

This is what I said Roadhog. Your comment is most unfair. I asked for a proper scientific test not the naive nonsense in AutoExpress which makes the very mistake I referred to as far back as posting 39 and which has since been much better put by JBerks.

Unless you've been given a subsidised chip, why would you object to having the product properly appraised by an independent body? Why object to a proper scientific test based on a reasonable sample size and in controlled conditions.

Plenty of far cheaper products undergo proper testing. Shouldn't something which costs hundreds of pounds and may affect the working and longevity of our complex and expensive cars be simlarly tested before we all rush in? Why do you think it unreasonable to want proper testing?

BTW, I also don't believe in fairies at the bottom of my garden, or Santa Claus or most anti-ageing products -not without some scientific proof. And I long ago gave up believing that snake oil would cure dandruff, baldness and piles.

 

[hawk20]

And Roadhog, what I said about car insurance is correct. See this from the Evolution Chips own website: -
What about my car insurance?
As we are sure you know, it is against the law not to inform your insurance company of any modifications you make to your vehicle, so to ease any concerns you may have about potential price increases, we have teamed up with one of the country’s best performance car insurers who have agreed to potentially leave your premiums from them unchanged if you have had tuning done by us. They can afford to do this as being a specialist insurers they fully understand and appreciate the benefits of tuning done by a professional and reputable company.
Click through to get an online quote or call now to find out more (don't forget to mention Evolution Chips please)...
Greenlight Insurance... 01277 263030

 

[whitenemesis]

This is what I said Roadhog. Your comment is most unfair. I asked for a proper scientific test not the naive nonsense in AutoExpress which makes the very mistake I referred to as far back as posting 39 and which has since been much better put by JBerks.

Unless you've been given a subsidised chip, why would you object to having the product properly appraised by an independent body? Why object to a proper scientific test based on a reasonable sample size and in controlled conditions.

Plenty of far cheaper products undergo proper testing. Shouldn't something which costs hundreds of pounds and may affect the working and longevity of our complex and expensive cars be simlarly tested before we all rush in? Why do you think it unreasonable to want proper testing?

BTW, I also don't believe in fairies at the bottom of my garden, or Santa Claus or most anti-ageing products -not without some scientific proof. And I long ago gave up believing that snake oil would cure dandruff, baldness and piles.

Waa!! What NO Santa!! :cry::cry:

 

[Xtractorfan]

Hawk the reason you dont believe it is because you cant explain it ..you see trees but no wood ..you see no ships but hardships .. life is a bitch ...what odds if some people dont achieve a 15% saving, but what if a lot of people do... I bet you could start an argument in an empty house..