Difference in economy

[GBSiena 1]

I have TWO ( I know, I know ) F10 535D’s

The first, FROG, is a 2010 with 245 kms ; we purchased this with 150km on it, we’ve had it about 4-5 years . It was remapped about 1 year into ownership.  Pre re-map mileage was approx 6.4 l/100km on my regular commute ( 35 minutes, mostly open road); post map long term mileaage ( more than a year between re-sets ) is dependably 7.2 l/100km

The second, GECKO, is a recent arrival – a 2011 that’s delivering 8 l /100ml and has NOT been remapped

I am unsure why the base economy between the 2 cars, same model, 1 year apart, varies from FROG’s pre-remap of mid 6’s to GECKO’s not remapped 8.  Almost exclusively the same driver ( me ) and same routes

 

Any ideas ?   Garry

[paulo 66]

1 hour ago, GBSiena said:

I have TWO ( I know, I know ) F10 535D’s

The first, FROG, is a 2010 with 245 kms ; we purchased this with 150km on it, we’ve had it about 4-5 years . It was remapped about 1 year into ownership.  Pre re-map mileage was approx 6.4 l/100km on my regular commute ( 35 minutes, mostly open road); post map long term mileaage ( more than a year between re-sets ) is dependably 7.2 l/100km

The second, GECKO, is a recent arrival – a 2011 that’s delivering 8 l /100ml and has NOT been remapped

I am unsure why the base economy between the 2 cars, same model, 1 year apart, varies from FROG’s pre-remap of mid 6’s to GECKO’s not remapped 8.  Almost exclusively the same driver ( me ) and same routes

 

Any ideas ?   Garry

Maybe check coolant temperature is getting hot enough to allow better efficiency, and that it is also allowing the DPF to do the required occasional burn-off? (needs to get to over 88 degrees I think).

I have an earlier e60 Diesel and it has had 2 x faulty thermostats over 80,00km and that resulted in worsening fuel economy until fixed. You will need to access the hidden dash menu to get readout of coolant temp or a scanner with real-time data readings.

[aja540i 1906]

Same size wheels and tyres?

[GorGasm 563]

Yep thermostat is definitely something to check.

[TonyT 48]

Different flow rates through the DPFs perhaps? ie. the 2011 one more clogged than the 2010.

[Olaf 3341]

In diesellandia as I am with my F25 X3 30D, I use Penrite diesel fuel biocide treatment, it kills the diesel bug and keeps your fuel lines and injectors clean. I can’t remember the actual concentration, about 30ml each time I fill up is a scratch over the recommended running dose.  On the side of the container are instructions for quantities for treating deep clean and also infestations.  Wouldn’t hurt to try a good dose of that through yours.  I certainly noticed a difference on mine when I first treated it.

have you established with a scanner when the last DPF Regen was?  I’d guess you’re getting it up to temp and sustained temp with a fully charged battery for it to kickoff when required.  If there’s anything preventing the regen in terms of operating state prerequisites, you might need to get that taken care of.

Also, check for recall - there’s a recall globally for n57 - something to do with coolant and DPF, I forget the details. Continental have the parts to do mine on back order.

HTH

[Spinner99 55]

On 8/29/2023 at 5:52 PM, Olaf said:

In diesellandia as I am with my F25 X3 30D, I use Penrite diesel fuel biocide treatment, it kills the diesel bug and keeps your fuel lines and injectors clean.

As an alternative to the biocide, have you seen one of these before?  https://dieselsolutions.co.nz/product/de-bug-l140/  

[Olaf 3341]

Interesting.  how often do you need to change the cartridge, and how much does that cost?  Also, isn't working pressure of 40psi far lower than the N57B30O1?

[Spinner99 55]

11 hours ago, Olaf said:

Interesting.  how often do you need to change the cartridge, and how much does that cost?  Also, isn't working pressure of 40psi far lower than the N57B30O1?

My understanding is there is no cartridge replace, it's a fit and forget device. There are no filters in it, no moving parts.  The diesel flows through magnets which destroy the "bug" on the way through.  I think the idea is it goes in your fuel line before any other filters, injectors etc so as to prevent said bug clogging your fuel filters etc.

Re the fuel pressure question, great question, i have no idea sorry    

[KwS 2429]

2 hours ago, Spinner99 said:

My understanding is there is no cartridge replace, it's a fit and forget device. There are no filters in it, no moving parts.  The diesel flows through magnets which destroy the "bug" on the way through.  I think the idea is it goes in your fuel line before any other filters, injectors etc so as to prevent said bug clogging your fuel filters etc.

Re the fuel pressure question, great question, i have no idea sorry    

Just use the tried and true biocides like Olaf mentioned. Magnets dont kill bugs. Thats like the old Peter Brock box of magic and wizardry. 

[E30 325i Rag-Top 2963]

Could be something has gone off the boil - injectors, turbos, fuel pump pressure. However, I would give the car a nice long hot run (not just cruising down the motorway) with a dose of injector cleaner in the tank, to give everything a good clear out. Probably do  filters first -air cleaner and fuel fuel being the key two.  See what it’s like after than then if no improvement, start checking things like the injectors and turbos.