If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed, registering will remove the in post advertisements. To start viewing messages,
select the forum that you want to visit from the selection below.
This means you should apply for your renewal now to avoid any disruptions to your membership whilst the renewal process is taking place! NOTE: If you have an auto renewing subscription this will happen automatically.
Above Forum Ad
Collapse
Announcement
Collapse
No announcement yet.
The MK6 Fuel Consumption (Most / Least per Tank) Thread
I just did a run to the Sunshine Coast and back.Fully loaded on the way up with a bit of fun while there and back today and averaged 9.15L/100KM.I'm pretty happy with that result considering it hovers around 14L/100 down here.
It ran like a top!I'm very happy with it.
Jokes aside, I guess the only way I'll find out is to fill the tank full to the brim, drive from the APR place, to work, and back, fill the car to the brim again, get the 'test' APR tune loaded, then do the trip again to see how it goes. Not the best way to test, but the best I could do - the web site says I can have the 'standard' map and stage one in th esystem and swap between the two, but I'd have to shell out lots of money for something I may not want.
What I would like to be able to do is get the car on a dyno and have the ECU custom mapped. That way the air/fuel ratio will be perfect for MY engine.
With all 'off the shelf' tunes, you do get improvements, but not the same as a custom map.
I know this works as I can download from the interweb thing maps for the powercommander on the bike, for the same setup my bike has, and it does show an improvement in power/driveability on the dyno. There was also a 'basic' custom map done on the bike with the lamda probe after the link pipe so both cylinders recieved an 'average' to improve things - bike was up about 3hp over stock. Then the tuner did what I was paying for - a custom map for each cylinder (has to use 2 x lamda probes in the headers BEFORE the link piple). An extra 5hp at the rear wheel over the first basic map - note with some fiddling the 'average' map could have picked up at leat 2hp more than it did, but for a comparison to what the computer could tune to for the average V the separate cylinders, it was OK.
For the car to be custom mapped would not be a cheap exercise. You need some fancy gear to do car engines V motorcycles (principle is the same though, just the execution).
You would not run an engine lean to reduce pollution as it would produce increased levels of NOX. The best mixture for pollution reduction is stoichiometric (lambda of 1). Either richer or leaner than that and the catalytic converter effectiveness drops dramatically. Best power is normally made a bit richer than stoichiometric (lambda of 0.9) and best economy a bit leaner (lambda > 1). The only reason to run lean is to improve fuel economy.
Unfortunately, the only practical way to run lean AND meet the pollution regs is to use a special catalytic converter that can store the NOX produced when running lean and covert it later when conditions are more favourable. These special catalysts are poisoned by sulphur in the fuel so until Australia drops fuel sulphur below 5ppm we wont see this technology here. Current VW TSI engines sold in Aus DO NO run lean burn - they run a stoichiometric mixture over most of the operating range with a richer mixture at high power conditions to increase power and keep temperatures down.
I'm also very skeptical about reflashes improving economy under normal driving conditions for the folloiwing reasons:
a) The manufacturer invests millions on calibration and validation to ensure they get the best economy they can compatible withe meeting emissions regs and durability targets. Getting a lower number on that fuel economy sticker is important to them.
b) Economy in normal driving is all about efficiency at part load, and low to mid rpm. At these conditions the stock tune has to run stoichiometric to meet emissions. If an aftermarket tune was leaning it out at these conditions it would be at the expense of increased NOX emissions.
You could get better efficiency at high power conditions as these are not tested as part of the ADR test cycle, but only by leaning it out which will reduce component life (cat, turbo, valves, etc)
Where the equation WILL come back in favour of the remap is where the standard map is set very lean for the pollution factor.
Conversely, a stock tune may in fact run richer under certain circumstances. Many Japanese cars run notoriously rich under power (and can blow smoke from the unburnt fuel) in order to play it safe: a richer mixture with excess fuel will cool the engine internals; a car that runs too lean can generate too much heat and damage the internals.
In both my previous cars, the MKV Golf GTI and the 9N3 Polo GTI there were fuel savings with Stage 1. Significant savings with the Polo. Cause it has a K03 and has so much "driveability" down load with the tune, you never needed to put your foot down to get moving. (So SilvrFoxX, no a sprint booster instead of a stage 1 won't help, as effectively you'd always be putting your foot down, but getting less power and using more fuel).
There are so many guys with the Polo GTI and Stage 1 who have seen fuel savings within a few weeks of having it (not in the first weeks cause you're having too much fun). Best of all, you could switch back and forth between Stage 1 and Stock on that car and compare. With the Stage 1 I would constantly beat the VW fuel consumption rating, whilst still having my fun.
What about the Golf R?
I don't know... I didn't have the Stage 1 for long enough, and it's not switchable. I also had the Stage 1 at about 1500km, at which point the engine is still bedding in and fuel consumption is dropping anyway. So I never really got the opportunity to do any economy runs/tests etc.
Leave a comment: