So would a remap on a 540i actually increase the mpg or not?

[swiftpete]

I have a 1998 540i. Under my normal driving style, which involves basically razzing about in it, the mpg according to the OBC is 22.6. That's not very good so I started taking it a bit easier, cruise control at 70mph on motorways and no hard acceleration. Anyway, it's gone up to 24.5 which is a bit better but still not the best. I don't really want to get rid as I like the v8, just don't like putting in petrol every other minute. I know the remapping places claim you get better mpg after a remap, has anyone got any real life experience of this?
I would ideally like it to be able to get better mpg when I'm just cruising along and have a bit more power when I am in the mood for using it. If you have a 540i and have had this done, then all the better, tell me how it is!

[bmwdrivernigel]

I have had my e34 (4 litre) 540 chipped and delimited, mpg before was 22, since then it has dropped to 17mpg but that is more due to enjoying the extra grunt it has

[swiftpete]

I can imagine how that can happen! So did it make it feel faster to drive then? I've heard differing reports on how much noticeable difference there is.

[bmwdrivernigel]

It does'nt feel faster, it actually is faster ! There is better response when 'pressing on' and as its a manual it can be pushed a bit harder through the gears, 3rd and 4th are brilliant now, overtaking is a breeze. It was worth losing a few mpg purely for the fun factor.

[parksie]

Unbelievable as this may sound!!I had my 840 Supercharged 3 yrs ago, I needed the extra push & excepted that I'd suffer a bit with the economy!!

Driving modestly the moded car returns around 30-32 mpg on a 80/90 mpg cruise compared to 22-24 mpg pre conversion

OK it cost a few bob but this is a very nice surprise given I now have 405 BHP at my disposal should the economy not be an issue

[8Tech]

Remapping will increase power and driveability if it is done correctly but as for better fuel economy, this will only happen if you do not use the added power and response, so theoretically it could......but it won't. I remapped my E39 540 and it drives noticeably better.

8Tech.

[swiftpete]

If I'm driving like a normal person will it increase the economy though as I don't razz it all of the time. I like to chill out and relax some of the time, then when I'm in the mood go for it. I'm thinking of chipped uk as I heard they were pretty good at this if i do do it.

My other option is to not remap it and just sell it for something thats a bit better on fuel. I don't really want to do this though..

Car unfortunately is not a manual, it's an auto by the way, whatever difference that will make.

[madou]

8Tech said:

Remapping will increase power and driveability if it is done correctly but as for better fuel economy, this will only happen if you do not use the added power and response, so theoretically it could......but it won't. I remapped my E39 540 and it drives noticeably better.

8Tech.

Did you use a third party base map, or adapt the OEM map yourself ?

Previous thread on remapping the 4.4 V8 in the E39 540

Edited by madou on Thursday 15th May 08:19

[dxb335d]

Re-mapping a N/A enigne seems a little pointless to me. Minimal HP increase for quite a bit of dosh!!

Money would be better spent elsewhere!

N/A tuning is expensive!

[swiftpete]

Well I know you're always going to get more out of a turbo diesel. But not everybody has a turbo diesel. I was really hoping that people that had actually had it done would be able to reply with their observations.

Thanks to the people that have replied so far, it seems like it does make the car faster. No one seems to be saying much about mpg increase though.

[eliot]

22mpg is fine, doubt you will see much improvement. Lets face it, if it was that easy BMW would do it from the factory.
Lets assume you get a 1mpg improvement, you will save £118 in one year assuming you do 12k miles PA - how much does the remap cost ?

[dxb335d]

swiftpete said:

Well I know you're always going to get more out of a turbo diesel. But not everybody has a turbo diesel. I was really hoping that people that had actually had it done would be able to reply with their observations.

Thanks to the people that have replied so far, it seems like it does make the car faster. No one seems to be saying much about mpg increase though.

Any turbo engine will make good gains!

I just think for 400+ pounds for 10-15bhp seems a bit excessive! Money could be better spent elsewhere

[swiftpete]

Well this is what I'm trying to find out you see. I am fully aware that turbo engines give more gain than non turbo when it comes to remapping. Knowing that doesn't make a lot of difference when I'm asking if remapping an N/A engine can increase the mpg though.

Yeah, eliot saying what if I only get 1mpg more, what difference would it make...? I agree, it wouldn't make much. This is why I wanted people that have had theirs done to contribute and tell me what their real life experiences on it are rather than just assuming that it'll change by something!

Edited by swiftpete on Thursday 15th May 12:19

[dxb335d]

swiftpete said:

Well this is what I'm trying to find out you see. I am fully aware that turbo engines give more gain than non turbo when it comes to remapping. Knowing that doesn't make a lot of difference when I'm asking if remapping an N/A engine can increase the mpg though.

Yeah, eliot saying what if I only get 1mpg more, what difference would it make...? I agree, it wouldn't make much. This is why I wanted people that have had theirs done to contribute and tell me what their real life experiences on it are rather than just assuming that it'll change by something!

Edited by swiftpete on Thursday 15th May 12:19

For a 1mpg increase then its still not viable is it?!

It would tank a long while to reap the rewards!

[swiftpete]

No for a 1mpg increase it's not worth it. But my point is, if someone assumes it will probably be a 1 mpg increase, it's different to someone that owns the actual car and has had it remapped and says what it actually gets, rather than just someones assumptions of what it probably would do.

[eliot]

If it was 3-4 mpg (which would be worthwhile) - the manufacturer would of done it at the time.
They tend to make the OEM maps slightly richer so they are safer in terms of varing fuel quality. On the chevy LS1's, you can pull the fuel ratio down into the 13:1's, gain power and a little economy - but the onus is on the user from a longevity point of view.

ETA:
Get the supplier of the chip to provide the data and if they wont/cant then assume it makes no difference.

Edited by eliot on Thursday 15th May 13:14

[8Tech]

madou said:

8Tech said:

Remapping will increase power and driveability if it is done correctly but as for better fuel economy, this will only happen if you do not use the added power and response, so theoretically it could......but it won't. I remapped my E39 540 and it drives noticeably better.

8Tech.

Did you use a third party base map, or adapt the OEM map yourself ?

Previous thread on remapping the 4.4 V8 in the E39 540

Edited by madou on Thursday 15th May 08:19

I remap the system myself and on the auto, it works even better because it alters the transmission shift points and speed also.

As I have already said, it will not improve fuel economy. Unfortunately, if you want fuel economy, dont drive a V8.

I am interested to know also where you believe you would get similar power improvements for this cost elsewhere so for bang per buck its unbeatable.

Diesels and turbos respond better to chipping but I am not sure how a 200,000m chipped diesel car will be mechanically compared to a 200,000m V8 petrol. I would suspect the diesel would be well on its way to its 3rd pump and turbo, costs far outweighing the cost of the fuel savings.

[madou]

8Tech said:

madou said:

8Tech said:

Remapping will increase power and driveability if it is done correctly but as for better fuel economy, this will only happen if you do not use the added power and response, so theoretically it could......but it won't. I remapped my E39 540 and it drives noticeably better.

8Tech.

Did you use a third party base map, or adapt the OEM map yourself ?

Previous thread on remapping the 4.4 V8 in the E39 540

Edited by madou on Thursday 15th May 08:19

I remap the system myself and on the auto, it works even better because it alters the transmission shift points and speed also.

Do you have to do separate programming for the transmission, or is it adaptive ?

8Tech said:

As I have already said, it will not improve fuel economy. Unfortunately, if you want fuel economy, dont drive a V8.

8Tech said:

I am interested to know also where you believe you would get similar power improvements for this cost elsewhere so for bang per buck its unbeatable.

Evo-S remap claims 20 bhp increase for £349. You are fortunate to have the skills to do a custom map for yourself

[eliot]

8Tech said:

I remap the system myself and on the auto, it works even better because it alters the transmission shift points and speed also.

What tools/interfaces are required to do the remapping? So far I haven't seen any diy kit - not that i have been looking. Remapping the gearbox appeals.

[8Tech]

Sorry, don't know how to do multiple quote answers so here it goes all in one.

To do the reprogram you need a laptop connected through the serial port and the new program to be uploaded. Wipe the stock program from the ECU and store it on the laptop then download the new program and install it. There is no DIY kit.

The program does the engine and transmission all at the same time. Exactly as BMW designed the system to do for factory updates.

20 bhp is not overly optimistic, I got 17 bhp.