[ebirotedu]

I don’t think that’s a new feature for the Z4, and isn’t related to any sort of hybrid power train.

From a dealer website description of the Z4 M40i:

“ Brake Energy Regeneration recharges your battery as you decelerate, brake, or coast, and not as you accelerate, helping to improve your performance and fuel efficiency. While a sports car built around speed, both vehicles maintain an excellent fuel economy, with an EPA-estimated 32 MPG highway from the sDrive30i trim, and 31 MPG highway from the M40i.”

I read that to mean that the alternator is clutched such that it’s not adding drag during acceleration, and is engaged instead on decel where the added load benefits braking by adding drag to the driveline.

Originally Posted by Bimmerfun82

Brake regeneration

If you compare the M340i and the Z4 M40i standard features on BMW's website, they say exactly the same thing.

But the guides are unclear, so I'm still unsure.

[Bimmerfun82]

Originally Posted by gkgeiger

I do see the brake regeneration indicator in my instrument cluster, which is highlighted when coasting down. I’m just surprised that if my car is equipped with mild hybrid feature that bmw doesn’t say so.

You have a MY23? In comfort mode does the car feel like it’s slowing down a bit on its own, more than normal engine deceleration? If not, then the z4 doesn’t have a mild hybrid system. I can’t find anything online. So I’m thinking it doesn’t have it, and I stand corrected. I was assuming based on the MPG increase.

[gkgeiger]

Originally Posted by Bimmerfun82

You have a MY23? In comfort mode does the car feel like it’s slowing down a bit on its own, more than normal engine deceleration? If not, then the z4 doesn’t have a mild hybrid system. I can’t find anything online. So I’m thinking it doesn’t have it, and I stand corrected. I was assuming based on the MPG increase.

Yes, I have a MY23. I think ebirotedu has the explanation. Thanks all.

[RigaTony1982]

Originally Posted by Bimmerfun82

It’s a new change for the ‘23 MY for several models including the 3 series and Z and others. Did you see the article l shared?

My car was a 2021 with the 48v mild hybrid. There was an additional battery under the hood on the passenger side for the hybrid. It is not new for 2023 3 series. Was new for 2021.

[RavenGX]

Originally Posted by Bimmerfun82

Brake regeneration

If you compare the M340i and the Z4 M40i standard features on BMW's website, they say exactly the same thing.

But the guides are unclear, so I'm still unsure.

the brake regeneration thing has been there on my last 3 bmw's, so at least 9 yrs.
I think mild hybrid goes a step further than that and also uses the battery when starting at a red light for example to lower the emissions of the car.

On the 16 to 20i models you can really feel that kicking in, the battery start is faster than what it would be with the engine and you feel it jump a little and then slow down (at least that's what i think causes it ).

I'm pretty sure my 2019 Z4 doesn't have that, not sure about the newer models.

[Bimmerfun82]

Originally Posted by RavenGX

the brake regeneration thing has been there on my last 3 bmw's, so at least 9 yrs.
I think mild hybrid goes a step further than that and also uses the battery when starting at a red light for example to lower the emissions of the car.

On the 16 to 20i models you can really feel that kicking in, the battery start is faster than what it would be with the engine and you feel it jump a little and then slow down (at least that's what i think causes it ).

I'm pretty sure my 2019 Z4 doesn't have that, not sure about the newer models.

That’s right. The debate here was did they make the 2023 have a mild hybrid. Our x5 40i has it, and an article said they expanded in the 23 model year to the M340i. So then… the question was did they also expand to the Z4 M40i. Sounds like no.

[RavenGX]

i don't think they changed much except the colors and some trim pieces

[DavesZupra4]

No one noticed the gorgeous brand new 7 series in the back?

[RigaTony1982]

Originally Posted by Bimmerfun82

That’s right. The debate here was did they make the 2023 have a mild hybrid. Our x5 40i has it, and an article said they expanded in the 23 model year to the M340i. So then… the question was did they also expand to the Z4 M40i. Sounds like no.

The M340 had the mild hybrid before 2023. I had it on my 2021. You’d know if you had it. At low speeds when you start to slow down, you can feel it as it turns the engine off and it almost feel’s slightly electric in nature. In addition, while I’m not a fan of the auto start/stop, it is significantly less noticeable on the mild hybrid versus without.

[StanDiego]

Originally Posted by RigaTony1982

I don’t think the Z4 has the mild hybrid. I say this because on my M340, the button to disable the auto start/stop wasn’t there. Z4 still has it. This was one of the things they removed from the 3 series when they added the mild hybrid in 2021.

The Z4 30i is a "micro hybrid" with a second 12v lithium battery under the hood but no such technology in the M40i.

[JustChris]

Originally Posted by StanDiego

The Z4 30i is a "micro hybrid" with a second 12v lithium battery under the hood but no such technology in the M40i.

Yes, I think these 2nd batteries are related to the hood mechanism and thus convertible specific.
I’m not sure why I got excited the LCI and any Z4 are of course not Mild Hybrid cars like mos tor the saloon and SUV series.

Still counting down the days. …. 2 months to go!

[PinkNinja400Guy]

ebirotedu is correct about brake regen... it's present even on BMWs without the mild hybrid system.

Originally Posted by JustChris

Yes, I think these 2nd batteries are related to the hood mechanism and thus convertible specific.
I’m not sure why I got excited the LCI and any Z4 are of course not Mild Hybrid cars like mos tor the saloon and SUV series.

Still counting down the days. …. 2 months to go!

The 2nd battery is not convertible specific. It's used to meet the high electrical load that the electronics in modern BMWs require. Practically all G-series BMWs can have the 2nd battery depending on configuration. Vehicles with active roll stabilization and rear wheel steering (not the Z4) have a heavier duty version of the 2nd battery under the hood to meet the even greater electrical demands of those systems.

I'm guessing the Z4 40i doesn't have that 2nd battery because the engine may have a higher power alternator which can generate enough power.

[StanDiego]

Originally Posted by PinkNinja400Guy

ebirotedu is correct about brake regen... it's present even on BMWs without the mild hybrid system.



The 2nd battery is not convertible specific. It's used to meet the high electrical load that the electronics in modern BMWs require. Practically all G-series BMWs can have the 2nd battery depending on configuration. Vehicles with active roll stabilization and rear wheel steering (not the Z4) have a heavier duty version of the 2nd battery under the hood to meet the even greater electrical demands of those systems.

I'm guessing the Z4 40i doesn't have that 2nd battery because the engine may have a higher power alternator which can generate enough power.

"Benefits from the dual storage system:
• Reduced CO2
• Weight saving with regard to vehicle electrical system support with AGM battery
• Emergency starting function
The lithium ion battery can be charged or discharged with higher currents than a lead-acid battery.
In this way, more energy can be stored for example in coasting overrun mode and exported where
necessary. This results in a reduction in CO2 emissions.
If the dual storage system is installed instead of the vehicle electrical system support with lead-acid
battery, a weight saving of 17 kg (37 lbs) or 19 kg (42 lbs) is made, depending on the capacity of the
lead-acid battery.
If the starter battery is so flat that the engine cannot be started, the engine can if necessary be started
via the lithium ion battery.
CO2 potential through energy recovery (1-2 g/km)
The dual storage system improves the energy recover capability of the 12 V system. The energy
recovery power output increases from approx. 0.5 kW to approx. 2 kW. This enables a large part of the
base load in the vehicle to be compensated. In this way, the drivetrain is only subjected to minimal load
by the alternator during acceleration phases.
MSA start quality
The lithium ion battery increases the power output at the starter motor. Improved engine starting
reduces the engine vibrations.

"

[Amadeo]

Originally Posted by PinkNinja400Guy

ebirotedu is correct about brake regen... it's present even on BMWs without the mild hybrid system.



The 2nd battery is not convertible specific. It's used to meet the high electrical load that the electronics in modern BMWs require. Practically all G-series BMWs can have the 2nd battery depending on configuration. Vehicles with active roll stabilization and rear wheel steering (not the Z4) have a heavier duty version of the 2nd battery under the hood to meet the even greater electrical demands of those systems.

I'm guessing the Z4 40i doesn't have that 2nd battery because the engine may have a higher power alternator which can generate enough power.

Some more info

[StanDiego]

Originally Posted by Amadeo

Some more info

I'm not sure how much of that applies to the S30i. It makes reference to the N55 and N57 motors in the X5 (F15, F16) and 7 series (G11, G12), nothing on our B48 engine. There must be some commonality with the PCU but I've yet to find anything specific to the S30i.

[DPelletier]

Originally Posted by RavenGX

i don't think they changed much except the colors and some trim pieces

Agreed. There is nothing of the few very minor changes they've made since introduction to entice me to consider trading my 2020 for a newer model.....in fact with some options disappearing in the last while, I'm very happy to have my 2020.

Dave

[BEAR-AvHistory]

Originally Posted by DPelletier

Agreed. There is nothing of the few very minor changes they've made since introduction to entice me to consider trading my 2020 for a newer model.....in fact with some options disappearing in the last while, I'm very happy to have my 2020.

Dave

+1 on the 2020