The Supra will offer engine options that are similar to the Z4 but many believed that they would be customized to some extent. According to the catalog, the 3.0-liter turbo inline-six Supra engine will actually be very close to the engine in the new BMW X5.
The version in the Supra is dubbed the B58B30C and the complete assembly appears to be unique to the Supra—for now. Since the Z4 catalog has not been posted at this time, we cannot confirm if they share the whole assembly, but it’s probably safe to assume as much.
What we can confirm is that the catalog shows that the complete cylinder head with valves is a direct carryover from the new X5's engine as they have the exact same part number. The exhaust camshaft is shared with the X5 motor along with the intake camshaft which is also shared with various other BMW models that have a variant of the B58 engine and has the exact same part number as the one in the BMW 340i. The intake with charge air cooler is also shared with the engine from the X5.
The crankshaft and pistons are also shared with the X5 engine, while the connecting rods are a fairly standard part that has been used in various 3.0-liter BMWs since 2015. The story with the oil pan is similar as it has also been in use for the same motor since 2014 and is a common part number.
The oil pump is unique to the Supra, as is the turbocharger. The water pump and heat management module are shared with the X5.
Based on what we can see from the part numbers, it appears that BMW took the engine destined for the X5 and swapped out the oil pump and turbocharger along with maybe a few other smaller parts but the overall engines are very similar and share the majority of their parts. The engine and transmission mounts appear to be unique to the Supra while the transmission is listed as being the ZF 8HP51Z with its won unique part number. The engine computer, starter, and alternator are shared with the X5.
The fuel rail is shared with the X5 while the high pressure injectors are a common BMW part that has shown up in cars such as the current 5-Series and the Mini Clubman. The throttle body is shared with the X5.
The suspension is very similar to the current
5 Series but most of the part numbers appear to be unique. The wheel hub and bearing package is directly from that 5 Series and the VDP suspension controller comes from the M5. The supports and links for the rear sway bar comes from the i8.
Steering also looks very familiar so it is no surprise that the steering column is shared with the X3 and X4 although the steering rack appears to be unique to the Supra.
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Based on the parts we’ve spotted so far, it is apparent that the Supra is fundamentally a BMW vehicle and one that they’ve tried to build while using many of their existing parts. I expect that we will see these same parts on the Z4 and the only bits of Toyota that we will see here will be the badges and any custom tuning that they might have done on the ECU.
