20i & 30i - Msport and Msport Plus

T

True-Blue

Veteran
 Bristol/Bath
Is a 20i Msport with the Msport Plus pack mechanically the same as the 30i Msport with the Msport plus pack - I believe that the engine, turbo etc is the same but the 20i is software restricted like the E89 18i & 20i vs the 28i. Is that correct?

Also, does the 20i Msport have the same size brakes as the 30i? (Think I’ve worked this one out, see edit below)

And what size brakes does the Msport plus kit bring to the 20i & 30i - it’s not very clear from this - https://autocatalogarchive.com/wp-content/uploads/2019/03/BMW-Z4-2019-UK.pdf

Edit - it looks like the 20i Msport has smaller brakes than the 30i Msport, so is Msport Plus pack the Diff and Active suspension on 30i, plus the bigger Msport brakes on the 20i? If so, I’m guessing the pack for the 20i was more than for the 30i. I’m talking about the mechanicals, not the trim and wheels.

Thanks all 👍🏻
 
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B48 engine like N20 is just a remap on BMW’s power options…lost the will to follow the nuances of BMW’s marketing options..
 
While both models use the modular 2.0-liter four-cylinder B48 engine, there are crucial mechanical and hardware differences between the two versions. The power difference is more than just a software restriction.

Engine and Mechanical Differences
  • Compression Ratio: The pistons have a different shape. The 20i has a higher compression ratio of 11:1, while the 30i has a lower compression ratio of 10.2:1 (or 10:1 depending on the exact production year codes). The lower compression of the 30i allows the engine to run safely with significantly higher turbo boost without risking engine knock (detonation).
  • Turbo and Cooling: Depending on the specific production years and engine sub-codes (such as B48B20A versus B48B20B), the 30i often features a larger or differently tuned turbo setup and a revised cooling system to handle the extra heat from the higher boost.
  • Exhaust Manifold: In some variants of the 20i, the exhaust manifold is integrated directly into the cylinder head, whereas the more powerful 30i variants use an external manifold for better airflow.
 
Pademe said:
While both models use the modular 2.0-liter four-cylinder B48 engine, there are crucial mechanical and hardware differences between the two versions. The power difference is more than just a software restriction.

Engine and Mechanical Differences
  • Compression Ratio: The pistons have a different shape. The 20i has a higher compression ratio of 11:1, while the 30i has a lower compression ratio of 10.2:1 (or 10:1 depending on the exact production year codes). The lower compression of the 30i allows the engine to run safely with significantly higher turbo boost without risking engine knock (detonation).
  • Turbo and Cooling: Depending on the specific production years and engine sub-codes (such as B48B20A versus B48B20B), the 30i often features a larger or differently tuned turbo setup and a revised cooling system to handle the extra heat from the higher boost.
  • Exhaust Manifold: In some variants of the 20i, the exhaust manifold is integrated directly into the cylinder head, whereas the more powerful 30i variants use an external manifold for better airflow.
Click to expand...
Poorly researched AI …


I went and pulled the part numbers rather than guessing, and it’s worth posting because the answer isn’t what the internet says.

Pistons and cylinder head are the same part numbers across the G29 20i and 30i — the only splits in the head listing are RDE emissions content, nothing to do with output. So there’s no compression difference on this car and your original instinct was right: it is the software restriction, same story as the E89. Worth flagging because there’s a lot of material out there stating the 20i runs 11:1 against the 30i’s 10.2:1. That’s real for some B48 applications elsewhere in the range, but it doesn’t hold for the Z4 — which is a good reminder that spec sites repeat each other while the parts catalogue doesn’t.

On the brakes: with the M Sport brake option fitted, both cars get identical parts — 348×36 discs, same disc, pad and sensor numbers. So the M Sport Plus brakes aren’t a bigger brake on the 20i than the 30i; it’s the same hardware under the same option code. What differs between the cars is what’s standard versus what you had to tick, not what the option contains.

Happy to dig out the actual numbers if anyone wants them.
 
B21 said:
Worth flagging because there’s a lot of material out there stating the 20i runs 11:1 against the 30i’s 10.2:1. That’s real for some B48 applications elsewhere in the range, but it doesn’t hold for the Z4 — which is a good reminder that spec sites repeat each other while the parts catalogue doesn’t.
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Yep, my other car is a G20 330e. It seems to be a lottery between the A or B variant of the B48 in those cars. Thankfully mine has the B variant, so when I get around to tuning, I should be at around 425bhp 😃.
 
Just been looking at the build sheet of my 30i and it has these option codes if any use?
S2NH​
M Sport brake
S2T4​
M Sport differential
S2VF​
Adaptive M chassis
 
B21 said:
Pistons and cylinder head are the same part numbers across the G29 20i and 30i — the only splits in the head listing are RDE emissions content, nothing to do with output. So there’s no compression difference on this car and your original instinct was right: it is the software restriction, same story as the E89. Worth flagging because there’s a lot of material out there stating the 20i runs 11:1 against the 30i’s 10.2:1. That’s real for some B48 applications elsewhere in the range, but it doesn’t hold for the Z4.
Click to expand...
Seems you are right about the engine that the sDrive20i and 30i share the same B48B20B engine for the g29. I thought the 20i had the B48B20A variant.
 
Zed Baron said:
Just been looking at the build sheet of my 30i and it has these option codes if any use?
S2NH​
M Sport brake
S2T4​
M Sport differential
S2VF​
Adaptive M chassis
Click to expand...
I have the S3M2 M SPORT BRAKE, RED HIGH-GLOSS on my 30i.

Seems in 2022 BMW chaged the codes for the M Sport Brake
S2NH was the code for the blue M Sport Brake, since 2022 they are now S3M1 (blue) S3M2 (red) and S3M3 (black).

If I'm correct the M Sport Brakes are the same for the Z4 20i and 30i (not the case for some other BMW models wher some 30i have bigger forn discs), and should be the same as those from the m40i.

Front axle: 348 mm x 36 mm ventilated discs with fixed Brembo aluminum 4-piston calipers.
Rear axle: 345 mm x 24 mm ventilated discs with a floating 1-piston caliper (combined with the electronic parking brake)
 
Pademe said:
Seems you are right about the engine that the sDrive20i and 30i share the same B48B20B engine for the g29. I thought the 20i had the B48B20A variant.
Click to expand...
Always best to verify with trusted sources such as real.oem and TIS !
 
crz4 said:
My 20i from 2022 has the B48B20O1 motor according to the delivery list.
Click to expand...
The physical casting code (the base engine): If you look at the engine block of a European Z4 sDrive20i, you’ll see “B48B20B” stamped into the metal. That is exactly the same physical engine (including the pistons and cylinder head with the lower 10.2:1 compression ratio) as the 30i.

In its factory systems and on the options list, BMW assigns the 20i engine the code B48B20M1 to indicate that the software is tuned for the lower power output (197 pk).

For my 30i I have the option code B48D (B48B20D), but that seems this code is the broad, general engine code that BMW uses in its official service manuals and general parts catalog to indicate that the car has a B48 Technical Update.

The B48B20O1 code is the specific administrative code for that same engine, which is linked to the chassis number. The "O" indicates that this is the Upper Output (30i / 258 pk) variant of the B48D which corresponds with the claim the Z4 g29 uses the same engine hardware for the 20i and 30i.
There is an extremely high chance that on my specific factory certificate for the 30i it lists as B48B20O1.
 
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