Though the S58 is based on the B58TU only 10% of the components are the same.
BHPian karan561 recently shared this with other enthusiasts.
The S58 engine in the BMW M4 is based on the B58TU engine from the M340i, it’s been possible to carry over several engine components from the B58TU standard production engine.
Video highlights the same & charts the similarities, differences & part sharing between these two engines featuring the BMW G20 M340i which is the M Performance model & G82 BMW M4 from the BMW M stable
Introduction
The BMW B58 engine is found in many cars like the M340i, X3M40i, X4 M40i, Toyota Supra etc. & the BMW S58 engine is found in cars like the M3, M4, X3M, X4M etc. However, today’s discussion is going to focus on 2 cars with specs. as under;
G20 M340i is a M Performance BMW with the B58TU (Engine Code: B58B30O1) producing 382 HP.
&
G82 M4 is a M Power BMW from the M stable with the BMW S58 (Engine Code: S58B30T0) producing 510 HP (Competition Spec.)
Though the S58 is based on the B58TU only 10% of the components are the same & 90% are different or new or present in some sort of an upgrade.
Let’s discuss the Similarities first:
- Chain Drive is the same for both these engines
- Intake Valves are the same just some material changes to adapt to the S58.
- VANOS concept is the same & carried over with some adaptations
- Injectors are Same
- DME is the same for both the cars
Differences:
- S58 gets a New Cylinder Head Gasket
- S58 has 2 Turbo Chargers whereas the B58 is a single turbo engine.
- S58 gets 2 Air Intake Ducts v/s 1 in the B58TU
- New CrankCase
- Forged Crankshaft (LightWeight)
- Forged Pistons
- A New Exhaust system
- New Cooling System
In addition to the above changes & adaptations the S58 gets some changes in the Oil supply (Additional Oil Sump lid) & a new (Single Stage) Vacuum Pump
So the core narrative around the G82 M4 or the G80 M3 has been about its styling and how controversial its front nose is, but in the middle of all this, we should not forget how fantastic it is to drive.
So I have driven the M4 on a couple of occasions previously, once on a drive organised by my dealership and the 2nd time at a track day event. Both times I have had the opportunity to go all out and experience the power of the S58. But this drive was about how it drives in regular local city conditions at moderately brisk speeds.
Immediate impressions about the B58 v/s S58 topic is that the B58 feels more refined & relaxed in the city, whereas the S58 feels more raw & eager.
The torque down under & mid-range feels more abundant v/s the B58.
B58 redlines @ 7000 rpm whereas the S58 has a 7500 rpm redline.
Quick talk about the exhaust, my M340i with the M Performance exhaust sounds better than the stock M4 S58, it’s true. Both engines sound similarly good but in this car, the OPF restricts the drama. Maybe an OPF delete should be considered for the M4 owners.
Overall the S58 in the M4 feels like a typical M Car engine where the performance is mega, Limits are approachable & most importantly it’s easy to drive fast.
Final Thoughts
If these cars were into bodybuilding then the B58 is only on protein shakes and a natural whereas the S58 is the one on steroids. To conclude things it would be fair to say that the B58 is the leader in 6-cyl technology for non-M Cars, whereas the S58 is bigger on power having a proper Motorsport inclination opening up the possibilities for the tuning world and aftermarket modifications. So the right way to say is that the S58 engine is the more heavy-duty B58 engine & the B58 has heavy-duty potential.
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