Re-map, And Improved Mpg?
Now this is going to be contraversial.. and burn me down in flames if you must but this is a sore point for me and coming from a mechanical point of view and pure real world physics . . . . .
Snake oil if you ask me. . . (not BHP gains . . . . . but MPG improvement)
Simple physics. .... Power in an engine equals air plus fuel plus compression/ignition.
So how can less fuel give more power?
In a diesel, power comes from injector timing/duration/ fuel quantity. Plus pressurized air from the turbo. Ignition occurs from cylinder pressure allone.
Petrol uses lower compression and a spark plug to ignite the petrol/air mix. A turbo adds high pressure air into the mix. (stoichiometric ratio)
The engine map deals with all of the sensors, timings, temperatures, profiles, loads Etc to deliver the most efficient power/tourq for the load applied to the engine and the drivers requested power demands....ie accelerator peddle position.
I think the engine mappers are smudging the offsets of the rail pressure etc and mpg offsets to show a false mpg readout on the dash and wild claims of increased mpgs etc ..... but increasing bhp by pushing the engine into it upper limits.
Only true comparisons of a whole tank of fuel vs miles over a set route can be compared.... ie track conditions . . . Before map. And after map.
Now on the other Side I do understand that running the engine in a higher power band will result in a more efficient running due to less low end drag and low revs gear changes...... but ultimately the higher Power band will use more fuel for that efficiency.
Have you ever heard of diesel wash in a mapped motor? (Diesel mixing with the engine oil) why? More diesel injected for longer. ... that's why you need to change your oil more often.
What about the rear tail pipe of
Some mapped motors?? Have you ever noticed thick black soot in the exhuast? Or even black soot around the bumper?
Or even black smoke under hard acceleration when your behind them . . . . . Why ? unburnt fuel from the over fueling of the engine to create as much bhp as possible . . . .... but all that black soot is not saving you mpg's.
Both the above are more obvious in older motors as newer motors have DPF or Cats to strip out the black soot and give the appearance of a clean running engine.
Then there are the propper pro mappers that claims great bhp gains, like stage 1 Etc..
Then stage 2 with a new cam. Then stage 3 with bigger turbo and new exhaust Etc... dyno runs the lot....... those guys are truly experts and know what there doing..... but rairly claim a reduction in fuel consumption.
In my previous experience over the years....... More power means more fuel. Diesel or petrol....
Then there is the specific T6 argument. on the TDI 4 engine options from 84-204ps, but all 2ltrs . . . so hows that if the displacement is the same....? well the map is the main thing as well as bi-turbo and in injectors among-st other things are changed as you go up the range. The 204 ps even has a twin piston high pressure diesel pump. . . . . . . so could you program a 204ps map into a 84ps EUC?.. No. But you could possibly run the 102ps map on a 84ps hardware setup. you could run the 150ps map on a 102.. . . . the thing is its not all about ecu mapping. the hardware needs to be changed to suite the new power levels. . . . How can a 150 be mapped to 204 when the factory 204 has a biturbo, bigger rail and pressure pump, water cooled charge cooler etc and other hardware.? So how does a £500 map make a 150ps run at 204ps? by pushing it to its very max for the hardware . . . . The true upgrade would be a ton of new hardware costing £0000`s. Main dealers know this and thats why warrenty can go out the window when you take your van in with a smoky clanky engine and they realise its been mapped . . . . . its being run outside of it designed sweet spot for a long life engine.
But were getting off track here. The question was improved MPG . . . .
So prove me wrong with facts , I'm all ears..... . .But that's my personal take on matters.
Snake oil if you ask me. . . (not BHP gains . . . . . but MPG improvement)
Simple physics. .... Power in an engine equals air plus fuel plus compression/ignition.
So how can less fuel give more power?
In a diesel, power comes from injector timing/duration/ fuel quantity. Plus pressurized air from the turbo. Ignition occurs from cylinder pressure allone.
Petrol uses lower compression and a spark plug to ignite the petrol/air mix. A turbo adds high pressure air into the mix. (stoichiometric ratio)
The engine map deals with all of the sensors, timings, temperatures, profiles, loads Etc to deliver the most efficient power/tourq for the load applied to the engine and the drivers requested power demands....ie accelerator peddle position.
I think the engine mappers are smudging the offsets of the rail pressure etc and mpg offsets to show a false mpg readout on the dash and wild claims of increased mpgs etc ..... but increasing bhp by pushing the engine into it upper limits.
Only true comparisons of a whole tank of fuel vs miles over a set route can be compared.... ie track conditions . . . Before map. And after map.
Now on the other Side I do understand that running the engine in a higher power band will result in a more efficient running due to less low end drag and low revs gear changes...... but ultimately the higher Power band will use more fuel for that efficiency.
Have you ever heard of diesel wash in a mapped motor? (Diesel mixing with the engine oil) why? More diesel injected for longer. ... that's why you need to change your oil more often.
What about the rear tail pipe of
Some mapped motors?? Have you ever noticed thick black soot in the exhuast? Or even black soot around the bumper?
Or even black smoke under hard acceleration when your behind them . . . . . Why ? unburnt fuel from the over fueling of the engine to create as much bhp as possible . . . .... but all that black soot is not saving you mpg's.
Both the above are more obvious in older motors as newer motors have DPF or Cats to strip out the black soot and give the appearance of a clean running engine.
Then there are the propper pro mappers that claims great bhp gains, like stage 1 Etc..
Then stage 2 with a new cam. Then stage 3 with bigger turbo and new exhaust Etc... dyno runs the lot....... those guys are truly experts and know what there doing..... but rairly claim a reduction in fuel consumption.
In my previous experience over the years....... More power means more fuel. Diesel or petrol....
Then there is the specific T6 argument. on the TDI 4 engine options from 84-204ps, but all 2ltrs . . . so hows that if the displacement is the same....? well the map is the main thing as well as bi-turbo and in injectors among-st other things are changed as you go up the range. The 204 ps even has a twin piston high pressure diesel pump. . . . . . . so could you program a 204ps map into a 84ps EUC?.. No. But you could possibly run the 102ps map on a 84ps hardware setup. you could run the 150ps map on a 102.. . . . the thing is its not all about ecu mapping. the hardware needs to be changed to suite the new power levels. . . . How can a 150 be mapped to 204 when the factory 204 has a biturbo, bigger rail and pressure pump, water cooled charge cooler etc and other hardware.? So how does a £500 map make a 150ps run at 204ps? by pushing it to its very max for the hardware . . . . The true upgrade would be a ton of new hardware costing £0000`s. Main dealers know this and thats why warrenty can go out the window when you take your van in with a smoky clanky engine and they realise its been mapped . . . . . its being run outside of it designed sweet spot for a long life engine.
But were getting off track here. The question was improved MPG . . . .
So prove me wrong with facts , I'm all ears..... . .But that's my personal take on matters.
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It's just a personal opinion
I think, they claim improved mpg because the driving attitude changes.
For ex --> for manual gear.. at 80 Km/H the shifter is in "5" when you try to gear up on "6", the engige rpm is too low.
After remapping you can use "6" at 80 Km/H that means more MPG
I think, they claim improved mpg because the driving attitude changes.
For ex --> for manual gear.. at 80 Km/H the shifter is in "5" when you try to gear up on "6", the engige rpm is too low.
After remapping you can use "6" at 80 Km/H that means more MPG
What they mean with "same driving conditions" ?
Did they test it with manual gearboxes and keep the same gear ?
If DSG, the increasing of torque after remap makes the DSG gear up so it is difficult to make a test.
I don't want to criticize anyone but who would do a remap if you say after remap, your consuption will increase
Professionnals tell that "you reduce your consumption" because you don't have to don't have to accelerate longer with more power and more torque.
That means that your driving conditions changed.
Did they test it with manual gearboxes and keep the same gear ?
If DSG, the increasing of torque after remap makes the DSG gear up so it is difficult to make a test.
I don't want to criticize anyone but who would do a remap if you say after remap, your consuption will increase
Professionnals tell that "you reduce your consumption" because you don't have to don't have to accelerate longer with more power and more torque.
That means that your driving conditions changed.
Depends what you want a remap for, power or economy.
Didn't ask tbh as wanted a decent increase if I decided to go ahead, presume they mean't driving the same way as usual, nothing scientific.
I had a 330d remapped years ago and that increased the power by 45bhp and economy by about 8 mpg, decent increase.
Didn't ask tbh as wanted a decent increase if I decided to go ahead, presume they mean't driving the same way as usual, nothing scientific.
I had a 330d remapped years ago and that increased the power by 45bhp and economy by about 8 mpg, decent increase.
I have a 150 T32 remapped by Pendle.
I have seen no improvement in economy, but then no appreciable deterioration either.
I have seen no improvement in economy, but then no appreciable deterioration either.
I have a revo stage 1 map on a 140 (to 185) 2.0pd Audi diesel.
The mpg definitely improved tank to tank after the remap. Chatting to the engineer that performed the remap he suggested the improved mpg was only there if I stayed below the original 140ps output, and was created as the map runs the engine slightly leaner, hotter and at higher pressure. Once you demand more than the original max power output of the engine you will of course be consuming more fuel.
However unless you drive like a total hooligan you actually spend very little time demanding more than the original max power output of the engine, so the net result is a slightly improved mpg.
The mpg definitely improved tank to tank after the remap. Chatting to the engineer that performed the remap he suggested the improved mpg was only there if I stayed below the original 140ps output, and was created as the map runs the engine slightly leaner, hotter and at higher pressure. Once you demand more than the original max power output of the engine you will of course be consuming more fuel.
However unless you drive like a total hooligan you actually spend very little time demanding more than the original max power output of the engine, so the net result is a slightly improved mpg.
It's not unusual for better mpg as the best calibration (map) for achieving NOx levels required by euro 5 or 6 legislation is not the most fuel efficient one. The people producing the remaps don't create ones that achieve the emission requirement they produce ones that have the fuelling optimised for power and this also runs more efficiently for mpg. You see the same when diesels started using dpf filters. The OEM could run the engine dirtier and therefore more fuel efficient and then use the dpf to clean up the emissions
I have had two previous diesel cars (not a great comparison I know!) remaped and both improved in economy.
As @Danger states above, if you drove them like your trousers were on fire, they were no better on diesel. If you drove normally, much better on diesel than they were originally.
However, a friend has a late euro 5 T5.1 84ps that has been remapped by pendle. He says it's much better/nicer to drive and has a slight improvement in economy over the original frugal nature.
As @Danger states above, if you drove them like your trousers were on fire, they were no better on diesel. If you drove normally, much better on diesel than they were originally.
However, a friend has a late euro 5 T5.1 84ps that has been remapped by pendle. He says it's much better/nicer to drive and has a slight improvement in economy over the original frugal nature.
Jacksonville
New Member
Hi All,
I'm new to the forum & an expat Brit living abroad. I have committed to buying a 2018 T6 Ocean next week with 204 PS here in Switzerland. Has there been any official statement from VW as to why the reduction in power to 199 PS on the T6.1?
I'm a little anxious about the situation as I don't want to buy a van that may have engine issues or emission challenges later which I may struggle to shift in let's say 3 years or when I decide to sell on.
Any thoughts on the topic? I look forward to hearing from any of you.
Jimmy
I'm new to the forum & an expat Brit living abroad. I have committed to buying a 2018 T6 Ocean next week with 204 PS here in Switzerland. Has there been any official statement from VW as to why the reduction in power to 199 PS on the T6.1?
I'm a little anxious about the situation as I don't want to buy a van that may have engine issues or emission challenges later which I may struggle to shift in let's say 3 years or when I decide to sell on.
Any thoughts on the topic? I look forward to hearing from any of you.
Jimmy
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