28i fuel consumption

[DonDon]

I was looking for a 20i, but have found a very nice 28i on a 63 plate. Driven sensibly, is the fuel consumption of the 28i much worse than the 20i? I know the official figures are the same, but I was wondering about the real world.

 

[Ole gits rule]

Quick check on Autotrader are showing the same on the combined cycle at 41mpg, not a surprise as the same engine with a different map

 

[B21]

Driven sensibly (yawn) no difference…

If you let the engine do it’s thing then it will be a little worse..

 

[DonDon]

Many thanks B21. I have paid a reservation fee and will pick it up later this week (all being well). I also meant to ask if there is any reason to use E5 petrol (e.g. Shell V Power), or is the car quite happy on E10. I assume there is no technical reason to avoid E10.

 

[matsmith749]

Loads of technical reasons why e10 is a worse idea than e5. Or even better e0.

If not sure why, best to google.

TLDR the only positive is it’s supposed to be a bit less polluting to the environment. Every other measure is worse for e10.

 

[matsmith749]

By every other measure I mean engine life, mpg, power output etc

 

[B21]

Many thanks B21. I have paid a reservation fee and will pick it up later this week (all being well). I also meant to ask if there is any reason to use E5 petrol (e.g. Shell V Power), or is the car quite happy on E10. I assume there is no technical reason to avoid E10.

E10 is perfectly OK for a stock N20 powered E89.

The engine’s tune is not needing, not expecting nor able to use the benefit of 98 / 99 Ron fuel..

If you re-map it then the tuner can take advantage of this to advance the ignition timing a little and gain 5-10 BHP more on the tune..

Some folks complain about E10 being hygroscopic but it’s 10% of something rather than 5% of something..

In the rest of the world they run on E85 ….wish I could get my hands on that in the UK

 

[Deepseaskateboard]

I always use Shell Vpower. Also started with redex. No idea if it makes any real world difference, probably like comparing tyre brands.

If you remapped it to use 99 or whatever Vpower is then got caught out and had to use regular gas, would that mess it up?

 

[B21]

I always use Shell Vpower. Also started with redex. No idea if it makes any real world difference, probably like comparing tyre brands.

If you remapped it to use 99 or whatever Vpower is then got caught out and had to use regular gas, would that mess it up?

If you’ve mapped it to take advantage of 98 / 99 Ron and you then use 95 the knock sensors will come into action sensing any knock due to pre-ignition and then backing off ignition timing in real time…it’s not elegant but saves melting pistons..

 

[Deepseaskateboard]

I always use Shell Vpower. Also started with redex. No idea if it makes any real world difference, probably like comparing tyre brands.

If you remapped it to use 99 or whatever Vpower is then got caught out and had to use regular gas, would that mess it up?

If you’ve mapped it to take advantage of 98 / 99 Ron and you then use 95 the knock sensors will come into action sensing any knock due to pre-ignition and then backing off ignition timing in real time…it’s not elegant but saves melting pistons..

Clever. I presume it puts it all back once you put in the good stuff!!

 

[enuff_zed]

I always use Shell Vpower. Also started with redex. No idea if it makes any real world difference, probably like comparing tyre brands.

If you remapped it to use 99 or whatever Vpower is then got caught out and had to use regular gas, would that mess it up?

If you’ve mapped it to take advantage of 98 / 99 Ron and you then use 95 the knock sensors will come into action sensing any knock due to pre-ignition and then backing off ignition timing in real time…it’s not elegant but saves melting pistons..

Clever. I presume it puts it all back once you put in the good stuff!!

I think by ‘real time’ he means it is constantly monitored and adjusted. Don’t think it drops to a default then resets. For example if you’re lightly cruising on the cheap stuff it could probably cope on the tuned figures, but when you put your foot down too heavily …..
If you’re an old fart like me you’ll remember hearing ‘pinking’ on old engines when you worked them hard, but you could stop it simply by balancing the throttle. Similar principle but more cleverly achieved these days

 

[B21]

If you’ve mapped it to take advantage of 98 / 99 Ron and you then use 95 the knock sensors will come into action sensing any knock due to pre-ignition and then backing off ignition timing in real time…it’s not elegant but saves melting pistons..

Clever. I presume it puts it all back once you put in the good stuff!!

I think by ‘real time’ he means it is constantly monitored and adjusted. Don’t think it drops to a default then resets. For example if you’re lightly cruising on the cheap stuff it could probably cope on the tuned figures, but when you put your foot down too heavily …..
If you’re an old fart like me you’ll remember hearing ‘pinking’ on old engines when you worked them hard, but you could stop it simply by balancing the throttle. Similar principle but more cleverly achieved these days :

 

[DonDon]

E10 is perfectly OK for a stock N20 powered E89.

Cheers. I know there are claimed to be issues in general, but I wanted to know if the E89 had been found to suffer in particular. I can now save lots by sticking to E10.

 

[B21]

E10 is perfectly OK for a stock N20 powered E89.

Cheers. I know there are claimed to be issues in general, but I wanted to know if the E89 had been found to suffer in particular. I can now save lots by sticking to E10.

The issue’s apply primarily to much earlier cars where the methanol content could attack rubber related components and act as a corrosive material for certain structures that typically had two or more dissimilar metals in close proximity…

It applies to BMWs made in the 20th century..

 

[matsmith749]

The issue’s apply primarily to much earlier cars where the methanol content could attack rubber related components and act as a corrosive material for certain structures that typically had two or more dissimilar metals in close proximity…

It applies to BMWs made in the 20th century..

That's such an oversimplified view of a complex topic.

Stating it with authority does not make it so.

e10 should not immediately break a >2010 vehicle (should not).

But it is always, in all circumstances:

: hygroscopic (absorbs water - then shoots it through your fuel system).
: less efficient (you will get less mpg with e10).
: a solvent - what the long term effects of this are remain to be seen.

 

[B21]

The issue’s apply primarily to much earlier cars where the methanol content could attack rubber related components and act as a corrosive material for certain structures that typically had two or more dissimilar metals in close proximity…

It applies to BMWs made in the 20th century..

That's such an oversimplified view of a complex topic.

Stating it with authority does not make it so.

From BMW UK..

"Can I fill my BMW with E10 petrol?
Every petrol engine BMW can use E10 fuel without ill effects but owners of some BMW cars that pre-date 1994 manufacture should closely follow the owner's handbook instructions by maintaining use of 97+ Octane Super-Unleaded which will now be labelled as E5 on petrol station forecourts. "

Do you regard the manufacturer as authorative?

 

[matsmith749]

No, all the points I made remain true & are not disputed by BMW or any other manufacturer.

Facts are facts - make your own decision.

If you think back over the years there are countless expensive legal cases that have been won against BMW & other car makers for wrongly making such asertions.

Ford - ‘these brakes are safe’
VW et all - ‘these diesels do 60mpg’

It invalidates your warranty to use any kind of fuel additive in most brands of car. Why do they do that?

I rest my case.

 

[B21]

Not sure where you are coming from..in the US and the rest of the world where E85/E50/E30 is prevalent people are tipping it into their BMWs with no apparent issues..

Given that almost every BMW in the UK has been fuelled with either E5 or E10 fuel for many many years I fail to grasp where for the purposes of the Op's question "can I use E10 fuel!" the simple anser is yes..it doesn't in this case need a complex and negative answer.

So what you are saying to the OP is that he should spend more on fuel in the absence of any documented evidence to the contrary and the full endorsement of the manufacturer and design authority?

To address your 'facts'..which I see you edited today!

yes methanol is hygroscopic...actually turbo cars run better with a bit of water, hence why we have water injection as used by certain BMW M4 models..if you are worried about water then keep your tank full..we are not talking about some old banger that spends it life with a 1/4 of a tank sat for years..

yes the volumetric efficiency is worse.. fuel consumption increases by around 0.7%..so here Shell 98 is 169.9..Shell 95 is 147.9..

That 0.7% impairment means that the £1.47.9 is really costing £1.49.1 a litre which is still cheaper than £1.699

Hate to point this out but every compound in petrol is a solvent..

TTFN

 

[matsmith749]

OPs original question was ‘is there any technical reason why not’.

It’s a debate that’s being doing the rounds for a while - I don’t just dismiss it.