[NxTH]

I suspect there will not be a lot of traffic here seeing how small amount of these cars were ever made, but knowledge is power regardless. Often times people don't even know this car exists, and deny its existence when hearing about it. "335i was never a hybrid", yet here it is.

All of the information below is also featured in a POV drive I just released, but here is every important detail we know in text form. Feel free to discuss the car and ask for help here.

The BMW Active Hybrid 3 is one of the rarest BMW's today with a global production of only 5,105 manufactured cars. The "AH3" is built on 335i with the N55 engine and F30 chassis, adding a High-Voltage battery on top for extra 55 horsepower. As a counter, there is a weight-addition from the battery.

As of 2022, if your high-voltage battery dies, you would be quoted around $10,000 for a replacement in the U.S, whereas in Finland the replacement is 2,600 €. Other EU countries hover around 6,000 €. The Active Hybrid 3 might not be worth it for Americans unless the battery has already been changed or you find a salvaged battery. The 8-year warranty period has just run out. In the EU I'd say it's highly worth it. At this point it's cheaper to ship the car from the US to Finland and have the work done than do it locally in the US.

So why would you buy an Active Hybrid 3 instead of a 335i? Used AH3's are typically well equipped, nearly maxed, and tax is cheap due to it being a hybrid. However, the vehicle doesn't arguably save you any gas. It is simply not an economic car; The hybrid battery is there to provide additional 55 horsepower and more torque over the 335i. In some cases, it uses even more fuel than a regular 335i. AH3 can be driven in electric mode, but only for 2.5 miles at a time. It recharges itself, so it's not a plug-in. Driving like this is however not the point of the car. You could argue the AH3 was nothing more but a test-run of the hybrid system. Owners however aren't disappointed.

If you are considering a 335i, but run into AH3's, you might want to consider them. These are incredibly fun cars to drive, and usually loaded with extras and well kept. Most of your typical mods and bolt-ons that would work on a 335i, work on the Active Hybrid 3. Your only concern should be the cost of a new high-voltage battery if and when it dies. Nobody really knows how long they will last, but a lot of high mileage AH3's are around with the original battery. Your country makes all the difference here. Ask your local dealer for a price before purchasing the car for ease of mind. In Finland's case, 2,600€ is definitely more than worth it to keep the car running. Note: The car does not run at all without the HV-Battery, and it can’t be disabled.

Here is some data on the HV-batteries lifespan I have gathered:


xHP and Bootmod3 are supported. Installing Downpipes and charge pipes doesn’t differ from a 335i.

F30 335i & Active Hybrid 3 differences:

- AH3 has a High-Voltage, AGM (95Ah) & AUX (44Ah) batteries. HV battery eats trunk space ⅓ worth. The AUX battery sits on top of the AGM-battery in the trunk. These can work up to ~10 years.
- A/C works with the engine off. A/C pre-cool with fob.
- AH3’s all-electric driving range of up to 2.5 miles (4 km’s)
- No Start & Stop button. S&S and electric driving can be disabled with the shifter pushed left in Sport mode. Do not attempt to code S&S off, it will glitch the car.
- Lower Pressure Fuel Pump is different.
- Main Radiator is different.
- Cooling Connection to Electric Motor interferes with larger turbos.
- Subwoofer fitment is limited in the trunk due to space.
- No Launch Control
- iDrive’s Hybrid menu (Power delivery, ECO settings & consumption)
- Minor visual exterior / interior differences such as badging.
- Gearbox Input torque increased to max. 700 Nm
- Transmission oil changes are a must on this car every ~50K miles.
- Bootmod3 burbles cause harsh engine-braking. Safe to use, but can be considered uncomfortable as the car no longer slows down smoothly. Problem goes away when burbles are disabled. I tested a few versions with the Bootmod3 developers, but we were unable to fix the issue. I don’t think it’s all that bad.

Stage 1 Horsepower 425 hp (Stock 340 hp)
Stage 1 Torque 523 nm (Stock 450 nm)
Stage 1 0-60 mp/h | 0-100 km/h: 4.5s (Stock 5.3s)

I have owned mine for about a year (2013 RWD at 99K miles, USA Import), and had the left mirror signal die on me. Nothing else yet.

Some notes specific to the AH3:

The HV-Battery can sometimes go “out of sync”. If you park the car for a short time (30 seconds) to pick up mail or something and start moving again soon, you get a Drivetrain Malfunction and the Hybrid motor doesn’t engage until you turn the car off and back on. It simply doesn't know what to do if the electric motor doesn't start when it should. Never had anything big come out of this, it seems like a bug in the ECU.

Sometimes in damp weather you can also get the same error, as the hybrid motor refuses to kick in due to moisture. This can be fixed for a few years at the dealer by cleaning the battery contacts.

There are also two other variations of the car. Active Hybrid 5 & Active Hybrid 7 which are even more rare.

More information & POV drive in Finland:

[Vetix]

Are you sure that a new High Voltage Battery is so cheap in Finland? Because I informed myself and what i heard in Germany its really expensive like 8k
Nice Video!

[NxTH]

Originally Posted by Vetix

Are you sure that a new High Voltage Battery is so cheap in Finland? Because I informed myself and what i heard in Germany its really expensive like 8k
Nice Video!

I asked the BMW dealer themselves, so unless they are lying, it's just over 2K €.

[Davem4]

Just bought one yesterday that needs a battery and I got it ordered from bmw for $3500 and will be here nov 1st from Germany

[okayekam]

I have a AH3 that I’m modding.
Do you, by chance, know if the suspension bolts from a 335i would transfer to a AH3? I was wanting to do the 3H Air Lift Performance Kit, however, not e enough data to see if fitment would work. I used to have a 328i that I modded over to an M3, and I know since the 328i and 335i were both F30’s, pretty much everything on my car was able to swap over. Suspension is just huge, it’s not something I want to play with. My racing suspension kit would be around $4.5K, so I need to be sure about the ability to fit it.

[NxTH]

Originally Posted by okayekam

I have a AH3 that I’m modding.
Do you, by chance, know if the suspension bolts from a 335i would transfer to a AH3? I was wanting to do the 3H Air Lift Performance Kit, however, not e enough data to see if fitment would work. I used to have a 328i that I modded over to an M3, and I know since the 328i and 335i were both F30’s, pretty much everything on my car was able to swap over. Suspension is just huge, it’s not something I want to play with. My racing suspension kit would be around $4.5K, so I need to be sure about the ability to fit it.

One thing to take into consideration is the weight of the hybrid battery, which probably plays into suspension parts.

[okayekam]

Originally Posted by Nico-

One thing to take into consideration is the weight of the hybrid battery, which probably plays into suspension parts.

Yeah, I was definitely thinking about that, since the AH3 is a couple hundred pounds heavier. That was my biggest concern trying to get one that would fit a 335i - was the ability for it to fully and properly support the hybrid parts in the rear

[NxTH]

Originally Posted by okayekam

Yeah, I was definitely thinking about that, since the AH3 is a couple hundred pounds heavier. That was my biggest concern trying to get one that would fit a 335i - was the ability for it to fully and properly support the hybrid parts in the rear

You need springs specifically made for AH3, from manufacturers like eibach.

[Mikewrite]

Today I learned another difference in another thread: The electric motor has its own cooling system, with coolant accessed via a small dome-shaped black tank just behind the white engine-coolant expansion tank. See pic.

I have an M Sport trim of the 2013 AH3, and I recently learned the hard way that replacing a broken charge pipe to the intake is no joke. Unlike on other trims, it requires removing an AC line to remove the pipe, then recharging the AC refrigerant after replacing the charge pipe, which adds a good bit of labor. My indy shop charged me $1,100 for this repair.

[Mikewrite]

Couple more M Sport differences:

- No fog lights, presumably to increase air flow into the braking ducts?

- The engine air filter is a different part number. I don't understand the difference, as the filters don't look different to me than the non-M Sport ones, but BMW calls for the filter specific to M Sport trim.

[NxTH]

Originally Posted by Mikewrite

Today I learned another difference in another thread: The electric motor has its own cooling system, with coolant accessed via a small dome-shaped black tank just behind the white engine-coolant expansion tank. See pic.

I have never even noticed that and my car has gone through coolant flushes already. Is this something I need to check? Does it run its own coolant or is it connected to the whole system? How do you take care of this coolant and where's the MIN-MAX shown? Owners manual doesn't show this reservoir at all.

[Mikewrite]

There's a little Min-Max thingie inside mine. From https://www.realoem.com/bmw/enUS/sho...diagId=17_0689 it seems that it is its own closed system. As I just learned of this yesterday I don't know about maintenance but next time my shop services my coolant I will point this system out to them so they can find out what BMW recommends. I assume it uses G48 coolant just like the engine coolant but am not 100% on that.

[NxTH]

Originally Posted by Mikewrite

There's a little Min-Max thingie inside mine. From https://www.realoem.com/bmw/enUS/sho...diagId=17_0689 it seems that it is its own closed system. As I just learned of this yesterday I don't know about maintenance but next time my shop services my coolant I will point this system out to them so they can find out what BMW recommends. I assume it uses G48 coolant just like the engine coolant but am not 100% on that.

Update here when you know more.

[YASBBYM3]

There are several hundred ActiveHybrid owners on the Facebook BMW ActiveHybrid Group who have seen most issues.

[Gee-Dog]

Does anyone have info on shock absorber part numbers for an AH3? Just looking to replace with OEM spec shocks, but having trouble finding what shocks these take.

[Mikewrite]

Try realoem.com. Enter your VIN for precise results on your particular vehicle.

[Gee-Dog]

Originally Posted by Mikewrite

Try realoem.com. Enter your VIN for precise results on your particular vehicle.

Tried that - the results were anything but precise.

[NxTH]

Originally Posted by Gee-Dog

Tried that - the results were anything but precise.

Searched for shock absorber. Do the same for your year and start opening the links, figuring them out.

[Mikewrite]

Yeah mine were under Front Axle and Rear Axle in the intial menu of diagrams.

I had my rears replaced and just let my indy shop do it. These things are electronically controlled on mine and I'm not messing with all that. Cost me $1,800 :-(

[NxTH]

Originally Posted by Mikewrite

There's a little Min-Max thingie inside mine. From https://www.realoem.com/bmw/enUS/sho...diagId=17_0689 it seems that it is its own closed system. As I just learned of this yesterday I don't know about maintenance but next time my shop services my coolant I will point this system out to them so they can find out what BMW recommends. I assume it uses G48 coolant just like the engine coolant but am not 100% on that.

Asked my mechanic today. Level was in the middle, and he said the system never needs to be flushed or topped off, unless there is a very specific problem with some of the parts that have to do with it, or you perform maintenance that requires emptying the coolant out.

[Gee-Dog]

Originally Posted by Gee-Dog

Does anyone have info on shock absorber part numbers for an AH3? Just looking to replace with OEM spec shocks, but having trouble finding what shocks these take.

For anyone looking for this info, the original shocks on my AH3 are:
Front - 31316791555
Rear - 335267911588

[Mikewrite]

Going down the oil rabbithole again. I've been using Liqui-Moly Leichtlauf High Tech 5w40, which is approved by the manufacturer for BMW-LL01.

But now I see that the Liqui-Moly picker widget says Special Tech 0w30 or 5w30 is recommended for my 2013 AH3, and those are BMW-LL01 FE oils. Hmm. So I randomly went over to the Amsoil picker widget and guess what, of their six Euro formulas they recommend their 0w30 - also a BMW-LL01 FE oil. They have a 5w30 Euro that's a BMW-LL04, which I'd rather use, but it's not an option for my car.

Why are LL01 FE oils being recommended? I read somewhere that the SAPS spec for that oil isn't as good as for LL01. And aren't 0w30 oils a bit thin for these high-powered turbo cars?