M51 vs B58

Side-by-side reliability comparison

Higher reliability score
B58 BEST 93/100
+25 points over M51
0 / 100
ACCEPTABLE M51 BMW
0 / 100
BEST B58 BMW

Specifications

M51
B58
Brand
BMW
BMW
Verdict
ACCEPTABLE
BEST
Reliability
68
93
Years
1991--2000
2015--present
Displacement
2497 cc
2998 cc
Layout
I6
I6
Type
Diesel
Petrol Turbo
Power
115--143 hp
326--387 hp
Known Issues
2
3
Total Risk Cost
€1,500--€3,700
€430--€1,000

Character

M51

"Pre-common-rail indirect injection diesel. Cast iron tractor engine. Injection pump main failure at 250k+ km. No swirl flaps. No DPF."

B58

"Possibly BMWs best engine ever. Forged internals, insane tuning (600hp+). 300k+ km."

Issues Comparison

M51 2

▲ HIGH
Injection pump hot start failure €500--€1,200 200,000 km--350,000 km
▲ HIGH
Cylinder head cracking €1,000--€2,500 200,000 km--350,000 km

B58 3

● MODERATE
Coolant expansion tank / line failure — early units €150--€350 60,000 km--120,000 km
○ MINOR
Plastic charge pipe crack €80--€200 60,000 km--150,000 km
○ MINOR
Valve cover gasket oil leak €200--€450 80,000 km--160,000 km

Models

M51 3

3 Series E36 1991--1996 5 Series E39 1996--2000 3 Series E36 1993--1999

B58 26

6 Series F13 2015--2018 6 Series G32 2017--2023 1 Series F20 2015--2016 3 Series F30 2015--2019 1 Series F20 2016--2019 5 Series F10 2016--2017 4 Series F32 2016--2020 2 Series F22 2016--2021 7 Series G11 2016--2022 GR Supra A90 2019--present X5 G05 2020--present 3 Series G20 2019--present X4 G02 2018--present X5 G05 2018--present X6 G06 2019--present X7 G07 2019--present GR Supra A90 2022--present 5 Series G30 2017--2023 8 Series G15 2018--present 2 Series G42 2022--present 4 Series G22 2020--present X3 G01 2017--2024 Z4 G29 2019--present 7 Series G70 2023--present 5 Series G60 2024--present 340i F30 LCI 2015--2019 Sedan
Full M51 Report Full B58 Report