[Graham3769]

Hello, I'm new to this site but not to the marque. Currently on my 6th BMW 3 series, but my first diesel, 320d M Sport. All my previous have been 6 pot petrol cars, chose this to cut fuel bills. I have been considering a remap but would like to pick ur brains about possible serious knock on effects eg turbo problems...
is there anyone out there that has experience of this or can put my concerns to rest...the car is 3yr old with 33,000miles and FBMWSH.

I'd appreciate any feedback.

[E90jonno]

Without a doubt do it i have the 318D and its really does change the car. its the best mod out there for a start when talking about £ to power gains. The turbo will hold up fine under the extra power as bmw never tune their parts to the max like Audi do on some of the cars. Even the clutch will still be fine. do it!!

[p0jy]

I've been thinkinhg the same thing....any other comments would be highly appreciated.

[Ads4]

I mapped mine last month and absolutely love the difference. I've always had my cars mapped before and the 320d has been crying out for more power since I bought it (9 months ago). The car is totally transformed now and i love it

[p0jy]

Is it true that the economy improves ?

[Ads4]

It is negligible and not the strongest reason for getting a map done tbh. I drive with a heavy right foot and have seen economy rise from 45ish to around 48mpg.

[TMP]

Most reputable remap's offer a money back trial and warranty.

Have a plenty of threads

[jagdeepj123]

definitely get it remapped - I would recommend it for any turbo charged car. I had it done on my own 335i hence can talk from experience:

You book an appointment and take your car to tuner.
They plug in a laptop to your car diagnostic port in driver's footwell (no need to even open the bonnet).
You read a magazine in the waiting room for an hour while map uploads.
You drive out with basically a brand new engine!
Optionally you can get a before/after dyno run so you can confirm the upgrade figures.

As previous posters have mentioned, you get most BHP increase for your buck (with turbo engines) and it's a quick, clean, non-physical upgrade.

I used Evolve based in Luton and had great experience, but I imagine all tuners would have a similar process (with only the maps being unique between vendors).

[kaishang]

I've seen people commenting that remaps, when performed on turbocharged cars, can reduce fuel consumption... I'm just not clear on how this can happen?

[dxb335d]

its obvious, and only by a small margin. Don't get a re-map for fuel consumption. Your doing it to unleash extra power/torque and to have it mapped for better driveability.

FUCK MPG, LOVE MPH

[dim_sum]

ooo man was plannin the same thing for my car but hopin that mpg would increase dues to the stupid fuel prices increasin lik crazy afta jan.............but i will still go under the remapp sometime soon lol

[kaishang]

Originally Posted by dxb335d

its obvious, and only by a small margin. Don't get a re-map for fuel consumption. Your doing it to unleash extra power/torque and to have it mapped for better driveability.

FUCK MPG, LOVE MPH

Mmm, but I don't see how you can have any fuel consumption improvement at all... where does the improvment come from? Does the map use a leaner fuel/air ratio? How? I can see how you can improve power and torque by increasing boost pressure of the turbo and I can see how you can make a car feel faster by changing gear change points but both of these would tend to increase fuel consumption.

And do people reporting improved fuel consumption measure the consumption by measuring fuel pumped into the tank and distance traveled or are they relying on the on-board computer?

[Jeff123]

DTUK seem to offer an "Eco Remap" that claims mpg increases of 10, 20, 30% depending upon where you are driving.

[kaishang]

30% is a major reduction in fuel consumption: you have to ask if it is that easy, why don't car manufacturers do it themselves?

[E90jonno]

More MPG because you use less to get to said speeds so if you don't change the way you drive from now and also get a remap you will see better mpg as not using as heavy a foot to get to say 30mph

[Graham3769]

im not bothered about increasing mpg, as mentioned in my original enquiry I'm used to to more thirsty cars anyway, my main concern is engine(turbo) longevity...

[gIzzE]

Originally Posted by kaishang

30% is a major reduction in fuel consumption: you have to ask if it is that easy, why don't car manufacturers do it themselves?

You don't think they do??


320d comes out with 118bhp which beats the A4s 110bhp, then the A4 gets 130bhp and new 320d gets 134bhp, then the A4 gets 148bhp and 320d gets 150bhp, then we see 164bhp and then new engine with 177bhp, then it increases to 184bhp and I bet we see 198bhp from that engine before it is replaced.*

It is called marketing, you release what you need to at the time to compete with what else is out there, and you make sure you leave plenty in reserve to upgrade when necessary.


You then have to consider that you may drive to the Middle East in your car where as I drive to the North Pole in mine, you see 60ºc and I see -55ºc, and I guess we both expect our cars to work properly at both temperature extremes and with the different grades of fuel we will be putting in??
The manufacturers have to play it very safe when it comes to power etc.

Also remember many countries tax you based on power and not emissions, so if the higher rate is 170ps you suddenly see why the 320d is still offered in some countires with 169PS.


All marketing, all about marketing.




*figures are off the top of my head by the way, but used to give an idea.

[Falmouthboy]

Originally Posted by gIzzE

You don't think they do??


320d comes out with 118bhp which beats the A4s 110bhp, then the A4 gets 130bhp and new 320d gets 134bhp, then the A4 gets 148bhp and 320d gets 150bhp, then we see 164bhp and then new engine with 177bhp, then it increases to 184bhp and I bet we see 198bhp from that engine before it is replaced.*

It is called marketing, you release what you need to at the time to compete with what else is out there, and you make sure you leave plenty in reserve to upgrade when necessary.


You then have to consider that you may drive to the Middle East in your car where as I drive to the North Pole in mine, you see 60ºc and I see -55ºc, and I guess we both expect our cars to work properly at both temperature extremes and with the different grades of fuel we will be putting in??
The manufacturers have to play it very safe when it comes to power etc.

Also remember many countries tax you based on power and not emissions, so if the higher rate is 170ps you suddenly see why the 320d is still offered in some countires with 169PS.


All marketing, all about marketing.




*figures are off the top of my head by the way, but used to give an idea.

Thanks for this - I was about to pose a similar question along the lines that if it were that simple, why don't BMW do it. Your point is well made.

[kaishang]

The point about arbitarily restricted power levels to meet marketing or power-based vehicle tax goals for certain end-user countries makes sense: but there is still no explaination about how a remap can reduce fuel consumption. What engine parameter does a remap change that leads to a reduction in fuel consumption?

Esp the 30% fuel consumption reduction claim - how does it happen? If it were a 30% power increase, you just use the turbo to boost cylinder pressures but where can a fuel saving come from?

[kaishang]

I've just had a read through some of the tuning threads - it seems that basic maps work by increasing the volume of fuel injected into the cylinder in each injection cycle. The basic maps do not appear to change turbo boost pressure.

However even the tuning box / map vendor states that fuel consumption on the OBC is calculated off the standard factory map and therefore a remap can lead to inaccurate OBC fuel consumption readings.

Infact following a remap, the OBC may report a reduction in fuel consumption due to lighter throttle inputs from the driver to achieve the same (or greater) performance. But the volume of fuel being injected to achieve that performance is MORE than it was before ie there will be a fuel consumption increase, not decrease.

If you want to calculate your fuel consumption following a remap, you need to note down the volume of fuel added when you refill at the pump and then note down your odometer readings. For direct comparisons, you would have needed to do this before the remap too. And since you can't replicate the exact driving conditions between remap vs non remap, you need to do it for several tank fills of fuel, say 10 tanks or more over similar conditions and in similar weather conditions.

In short - the way to get more power is by burning more fuel. This is what a remap does. It doesn't - at least from what I have read about how remaps function - reduce your fuel consumption. Post remap OBC fuel readouts are irrelevant to this discussion as they are not accurate following a remap.

[gIzzE]

I have had remaps that have increased the mpg slightly, not a great deal, but slightly, however, on my 1 series auto that made quite a bit of difference.
Before the map I got around 38mpg, but after the map I got around 44mpg, the other thing was the car always felt like it was slightly over revving before the map, that sort of rubber band effect you can get with autos, but after the map it changed gear quicker and felt snappier. You could also feel the extra torque between 1500-2500, and you didn't feel you needed to drive it anywhere near as hard.



These were measured figures not off the OBC.

[NJMARTYN]

had my 330d done by evolve just before xmas. went from 239bhp and around 600 torque up to 282bhp and 700 torque. she's much smoother to drive now than before, i think mainly because the power is more evenly distributed which means a more consistent acceleration which in turn means the turbo isn't required so frequently (which probably improved MPG?). She certainly puts your head into the headrest when you want it to! just watch those corners