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European vs US F-twins

patgm

New member
Does anyone know the specific differences between the European and US versions of the current generation of parallel twins that account for the differences in rated output? I know most people will want to point to Euro5, but the BMW website says that both the US and European model of the F900 are Euro5 compliant.

US Specs
https://www.bmwmotorcycles.com/en/models/roadster/f900r/technicaldata.html#/section-technical-data

UK Specs
https://www.bmw-motorrad.co.uk/en/models/roadster/f900r/technicaldata.html#/section-technical-data

I am wondering specifically if it is a fueling difference, cam profiles, ignition timing, exhaust tuning, measurement strategy, or some other difference.
 
I got this direct from BMW North America.. it's a different fuel map because the fuel in the US is generally of worse quality than the rest of the world. The engines are physically the, the same, just detuned.
That said, the ECUs are adaptive and will adjust for fuel. The US version calls out 87aki fuel in the owners handbook, I suspect that running 91/92 will bump the HP figure back up. In fact, if you read a handbook from another region it specifically says the power will be less in lower grades of fun than recommended, and every other region recommends premium. That makes me think that there is no difference at all, and they are just covering themselves legally for people that run cheap fuel and then say the bike is down on power.
 
Thanks for the information! I'm in California so unfortunately the best we have in an average station is 91 AKI. The manual is poorly formatted in the section that describes the recommended fuel grade, which is 'premium' normally, or 'regular' for the A2 version in europe, but if I am reading it correctly, it seems to suggest that while premium is "recommended" regular (87 aki) is acceptable too.

The spec pages I linked in the original post state 95 RON for the UK (90-91 AKI) and just "Premium unleaded" for the US.

Also found an article on MOA trying to clarify some of this in relation to literature on the 750 and 850 GS bikes.

https://www.bmwmoa.org/news/438324/Understanding-octane--AKI-MON-and-RON-oh-my.htm
 
China is a strategic adversary of the United States, so they de-rate the engines bound for the US market just to irritate us. :D
 
China is a strategic adversary of the United States, so they de-rate the engines bound for the US market just to irritate us. :D

So I guess it's a good thing that the engine management is Bosch then? Having come from the F800GS, it had plenty of it's own gremlins. For that matter having owned plenty of luxury European vehicles has taught me that it doesn't matter where it's made, everyone can make mistakes, ship them, and then ignore them.
 
Generally speaking, the difference between running 87 and 91 octane in any given engine will be ignition timing related to avoid pinging with lower octane fuel. The ECU will retard timing if pinging is sensed to avoid engine damage, but the retarded timing also results in slightly less hp.

I doubt most riders would ever notice the slight decrease in peak power but it might make a difference on the drag strip.
 
Generally speaking, the difference between running 87 and 91 octane in any given engine will be ignition timing related to avoid pinging with lower octane fuel. The ECU will retard timing if pinging is sensed to avoid engine damage, but the retarded timing also results in slightly less hp.

I doubt most riders would ever notice the slight decrease in peak power but it might make a difference on the drag strip.

I would agree with your statement, but the US and EUR manuals for these models claim a peak HP increase with 90 AKI fuel vs 87 AKI fuel.

https://manuals.bmw-motorrad.com/manuals

In the case of the USA version, only 87AKI E15 is listed as fuel.
 
I would agree with your statement, but the US and EUR manuals for these models claim a peak HP increase with 90 AKI fuel vs 87 AKI fuel.

https://manuals.bmw-motorrad.com/manuals

In the case of the USA version, only 87AKI E15 is listed as fuel.

Ah, I was looking at the manual for the 0K11 (EUR) rather than the 0K13 (US).

So I wonder, if you feed a US model 91aki or higher, will the ECU continue to advance the timing (when appropriate) until detonation is detected, or will it have a maximum advance where 87 would be expected to begin to knock?

It seems like if the timing would continue to advance, the manual would just say "90aki recommended, 87aki optional" like the European manual, though I assume the "optional equipment" that the Euro manual refers to is the A2 compliance package.
 
Ah, I was looking at the manual for the 0K11 (EUR) rather than the 0K13 (US).

So I wonder, if you feed a US model 91aki or higher, will the ECU continue to advance the timing (when appropriate) until detonation is detected, or will it have a maximum advance where 87 would be expected to begin to knock?

It seems like if the timing would continue to advance, the manual would just say "90aki recommended, 87aki optional" like the European manual, though I assume the "optional equipment" that the Euro manual refers to is the A2 compliance package.

Based on the optional fuel comments found in the later R1200/R1250 LC models, the ECU software appears to be "adaptive" to fuel octane rating. As I understand it, for the early R1200 LC models, dealerships could install the software modification. So, if the new F models have similar ECU programming as the current R1250's, changing fuel type (AKI) should produce to EUR model results.

Again, I don't understand how AKI rating is resulting in more power production from the same engine.
 
Based on the optional fuel comments found in the later R1200/R1250 LC models, the ECU software appears to be "adaptive" to fuel octane rating. As I understand it, for the early R1200 LC models, dealerships could install the software modification. So, if the new F models have similar ECU programming as the current R1250's, changing fuel type (AKI) should produce to EUR model results.

Again, I don't understand how AKI rating is resulting in more power production from the same engine.

I would expect the late models to have similar ECU programming, but hard to say for sure. It's pretty common for ECU controlled engines to produce different power numbers with different fuels, usually by advancing the ignition timing, though there may be other variables at play as well.

https://www.caranddriver.com/features/a28565486/honda-cr-v-vs-bmw-m5-ford-f-150-dodge-charger/
 
So I guess it's a good thing that the engine management is Bosch then? Having come from the F800GS, it had plenty of it's own gremlins. For that matter having owned plenty of luxury European vehicles has taught me that it doesn't matter where it's made, everyone can make mistakes, ship them, and then ignore them.

I’m not surprised to hear the Loncin engine has Bosch engine management. It’s consistent with china’s strategy of requiring chinese content and/or technology/transfer in order to have access to their markets. It is all part of a larger strategy that is targeting Germany specifically:

https://www.fdd.org/analysis/2020/10/14/made-in-germany-co-opted-by-china/
 
I’m not surprised to hear the Loncin engine has Bosch engine management. It’s consistent with china’s strategy of requiring chinese content and/or technology/transfer in order to have access to their markets. It is all part of a larger strategy that is targeting Germany specifically:

https://www.fdd.org/analysis/2020/10/14/made-in-germany-co-opted-by-china/

The throttle bodies, injectors, sensors and maybe even the ECU itself come from various suppliers, possibly Chinese, but the source code for the software to manage it all belongs to and is controlled by Bosch and licensed from them. I’d guess BMW is the license holder, not Loncin. BMW has other functionality in the managenent software that is unique to their requirements.
 
It didn't take much searching to decide that the FDD isn't exactly an altruistic source of information, but they're on the internet so,, ya know ;)

I think I'll use the tried and true fall back defense. If you don't like tech made in China, then what are you using to post on these boards? We're really good at saying what we want, but we're really bad when it comes to paying for it.
 
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