[Gdiddy23]

Originally Posted by 3erMan

But what's that button in place of the ASS on/off switch?



EDIT: Just noticed "HYBRID" and "ELECTRIC" mode buttons. W.T.F.?!?!?

EDIT EDIT: My bad on the picture. That's the 330e. Whew.

Is this for the 330e? That would explain those buttons

[3erMan]

Originally Posted by Gdiddy23

Is this for the 330e? That would explain those buttons

Yep. 330e. Apparently, the M340i still has Sport, Comfort, and EcoPro buttons, but no ASS on/off. Sounds like ASS will be on in Eco and Comfort and off in Sport.

[eforty6_m3]

Originally Posted by 3erMan

Yep. 330e. Apparently, the M340i still has Sport, Comfort, and EcoPro buttons, but no ASS on/off. Sounds like ASS will be on in Eco and Comfort and off in Sport.

I hope you're correct...

[50M]

Originally Posted by eforty6_m3

I hope you're correct...

I was expecting the 10 hp 48v battery to improve the 0-60 on the 2021 M340.

Seems like the 2021 M340's weight has gone up by 70 lbs / 35 kg. Which is probably why the 0-60 may have stayed the same.

[greekcs]

2021 M340i
https://www.bmwofbeverlyhills.com/ne...ab352ab63b.htm

[carguy19]

I'd like to know too. I'm hoping that the 2021's can be tuned just like the 2020's by sending in the DME... crossing fingers.

I have a 21 on order thats in production now. Mineral/oyster pp, dap, shadowline, remote start, HK and wireless charging. Oh and 19'' 791 wheels and painted spoiler.

[Colwill]

I've just taken delivery of my mineral grey, shadowline, M340d () and these are the specs for the diesel car: 335hp, 48V battery to help 'smooth out' the stop/start. It is very smooth when starting again after stopping at lights etc.

seems like there might be a printing error, not sure why the petrol would need the help at stop/start.

[Lonmon]

I just picked up my 2020 M340ix last Tuesday and spoke to the BMW "Genius" who said that it is an error in the specs listed that we have the 48v mild hybrid system. That will only be for a different engine combination (I can't remember which one he said). I brought it up because I noticed that all the 2021 M340i's I saw for sale had it listed as one of the features and they were listed as hybrids. I purposefully looked for a 2020 because I didn't want any extra complication with tuning the vehicle and noticed that there was no reported advantage in peformance or economy. It makes sense then that it was an error and the M340i in fact does not get the 48v hybrid system.

[Burrcold]

Originally Posted by Lonmon

I just picked up my 2020 M340ix last Tuesday and spoke to the BMW "Genius" who said that it is an error in the specs listed that we have the 48v mild hybrid system. That will only be for a different engine combination (I can't remember which one he said). I brought it up because I noticed that all the 2021 M340i's I saw for sale had it listed as one of the features and they were listed as hybrids. I purposefully looked for a 2020 because I didn't want any extra complication with tuning the vehicle and noticed that there was no reported advantage in peformance or economy. It makes sense then that it was an error and the M340i in fact does not get the 48v hybrid system.

But...the M340i does get a 48V mild hybrid for the 2021 models, so your "Genius" is not so smart.

[bSwiazzy]

Originally Posted by Burrcold

But...the M340i does get a 48V mild hybrid for the 2021 models, so your "Genius" is not so smart.

lol Burr is right there is a Mild Hybrid M340i.

it is in regards to the auto start stop. other than that no performance gains to my knowledge

[bSwiazzy]

Originally Posted by Colwill

I've just taken delivery of my mineral grey, shadowline, M340d () and these are the specs for the diesel car: 335hp, 48V battery to help 'smooth out' the stop/start. It is very smooth when starting again after stopping at lights etc.

seems like there might be a printing error, not sure why the petrol would need the help at stop/start.

so the auto start stop does have a little time when you take your foot off the brake and the engine turns back on. the mild hybrid smooths that out

if you are a never in eco pro mode or remember to press the auto start stop button in 2020 models then you wont know

but i drove the 2021 and there is no transition which is a good thing. i am around these cars everyday lol

[Lonmon]

Originally Posted by Burrcold

But...the M340i does get a 48V mild hybrid for the 2021 models, so your "Genius" is not so smart.

I thought it was strange that a company like BMW would have so much incorrect info spread around. The "Genius" was a very young looking nerdy type. Maybe he just did not know what he was talking about. Oh well, I stand corrected. The idea that it is only used to smooth out the start stop function makes sense with the lack of any performance specs being affected. I will say my 2020 seems to transition really smooth when the start stop functions in comfort mode. Hard to believe it needed this hybrid system to make it any better. I will say, I don't use it often.

[Lonmon]

According to Car and Drivers article about the M440i the 48v system it adds up to 11hp designed to aid the engine in areas before the turbo spools for a smoother transition of power. Does not mention the start stop system at all.

[bSwiazzy]

Originally Posted by Lonmon

According to Car and Drivers article about the M440i the 48v system it adds up to 11hp designed to aid the engine in areas before the turbo spools for a smoother transition of power. Does not mention the start stop system at all.

I can appreciate your response. with that being said, the there is no more auto start stop button in any 2021 M340i. you are probably right i could be wrong

the hp is still the same @ 382hp between the 2020s and 2021s with the mild hybrid

[Lonmon]

I think they meant 11hp worth of assistance. Not adding 11hp to the total output. I haven't seen the interior shots of the 21 in reference to the start stop button. I do believe that the hybrid system could be used for both, car and driver simply didn't mention it.

[Oxide_Touring]

Mine must be a MY 2020.9 then. VIN says 2021, its having the button and its not a mild hybrid. Production started late june, and was sent from Germany in july. Im in Europe btw

[THE3]

Originally Posted by Oxide_Touring

Mine must be a MY 2020.9 then. VIN says 2021, its having the button and its not a mild hybrid. Production started late june, and was sent from Germany in july. Im in Europe btw

I have 2021 M340i, with ASS button and it’s not MHEV. It was built end on July. The shipping of M340i MHEVs manufactured in Germany starts from November onwards, but my understanding is Mexico built M340i MHEV have been available in NA already for some time.

Here’s a 2021 M340i MHEV (Mexico built) https://www.elmhurstbmw.com/inventor...u9j0xm8b50316/

[BLG19]

Originally Posted by THE3

I have 2021 M340i, with ASS button and it’s not MHEV. It was built end on July. The shipping of M340i MHEVs manufactured in Germany starts from November onwards, but my understanding is Mexico built M340i MHEV have been available in NA already for some time.

I have a MY21 M340ix NA built in Mexico that finished production 8/14 (just took delivery last week). It does indeed have a 48v MH with NO ASS button.

I'm still curious with the OP's orginal question, on whether engine tunes would need to account for this new MEHV component or not.

[///Mobbin]

Took a test drive in a few 2021's with 48v MH and confirmed that in Sport mode the engine does not turn off at a stop, super smooth on/off in other modes, so imagine that is the MH doing it's job. If this is like other similar systems the added power is from the alternator/starter/generator device and adds the ~10hp to the crank/systems by belt drive. If that is the case I think tuning is likely unaffected by this system. FWIW Carbahn advertises their tune as working for 2021's.

[///Mobbin]

I found a good explanation of the mild hybrid system in the 5-series and assume it's the same for our cars: LINK

"48-Volt mild hybrid technology for six-cylinder engine models. A new mild hybrid system with a 48V starter-generator offers enhanced performance, better efficiency and improved driving comfort in the six-cylinder BMW 5 Series.

A 48V starter-generator and a second battery greatly increases the ways in which Brake Energy Regeneration can be utilized. When the driver releases the accelerator, the generator transforms the kinetic energy into electricity to be stored in the 48V battery.

Energy recuperation benefits even more when the Driving Experience Control switch is set to SPORT mode. The additional deceleration generated over and above the engine braking effect is also harnessed when the brakes are applied.

A specially designed braking system previously found in BMW’s plug-in-hybrid models enables the combination of electrical and mechanical deceleration to be deployed as required and with maximum efficiency at all times.

The recuperated energy accumulating in the 48V battery is supplied to the 12V electrical system and powers the lights, steering, power windows, ventilation, audio system and seat heating. In addition, the stored energy can be used to provide additional drive power when it is fed back to the 48V starter-generator.

The starter-generator then acts likes an electric drive unit that assists the engine, allowing it to operate within a more efficient range as frequently as possible and ensuring there are fewer peaks in fuel consumption. When the car is accelerating, the 48V starter-generator is able to offer the driver an electric boost effect that can instantly put an extra 11 hp on tap for more dynamic power delivery. The result is a sharper response off the line and quicker bursts of speed when accelerating.

A special feature of the mild hybrid system is the ability to charge the 48V battery from the generator while driving at a constant speed. This method of generating electricity by raising the engine’s load point is only employed when the battery charge is low and during phases when it does not have a detrimental effect on engine efficiency.

The 48V starter-generator has the additional benefit of allowing the engine to be switched off and started again very swiftly with less vibration. The result is improved comfort when the Auto Start Stop and coasting functions are in use. When the driver brakes for a stop, the engine can be switched off as soon as the car’s speed drops below 9 mph. And if the coasting function is activated, the engine is also completely shut off rather than just being decoupled from the drivetrain. This function is now operational at speeds between 16 – 99 mph and, on the new BMW 5 Series, it is available not just in ECO Pro mode but also COMFORT mode."

[Ilovemycar]

So I just got a 2021 M340i delivered. Today while I was driving, I experience one of the ways the 48v mild hybrid works. I was in 4th gear with low RPMs and as I pressed the accelerator, EBoost kicked in and helped the car accelerate faster. It was completely smooth. Also, when I shut down the car for short period of time, like when you go into cvs or supermarket, when I start the car, it's almost like the car reacts when it shuts down in auto start/stop. Very smooth.

[thaalrasha]

This probably helps C02 emissions ? You know that's a thing in EU... if you can lower a bit and put the car in a lower tax bracket that means it can lift off massive tax penalties in some EU countries... Performance wise might be rather useless.

edit: I checked out on the UK website, looks like the 440i Xdrive has lower C02 emissions of 178-175 while the 340i Xdrive is at 189-185 g/km... So that's actually significant in term of penalty taxes. (i'm guessing the tech data of the 340i wasn't updated yet)