BMW 3 Series B47 Diesel vs B48 Petrol: Which Should You Buy?

Choosing between a B47 diesel and B48 petrol BMW 3 Series is not simply a question of which engine has the better reputation. The right answer depends on journey length, annual distance, local emissions rules, maintenance evidence, and the condition of the individual car.

Use the BMW 3 Series buying guide for the complete vehicle, including suspension, electronics, gearbox, body condition, and service history.

Choose the B47 for suitable long-distance use

The B47 diesel makes sense when the car regularly reaches full temperature and completes longer journeys. It offers strong torque and fuel economy, but its DPF, EGR, sensors, and cooling system add dependencies that short-trip drivers may not support.

Inspect it with the BMW B47 powertrain guide and the detailed B47 DPF and EGR checks.

Choose the B48 for mixed or shorter journeys

The B48 petrol is often the simpler match for lower annual mileage, mixed driving, and frequent short journeys. It still needs evidence of correct oil service, stable cooling, healthy ignition, controlled oil leaks, and clean diagnostic data.

Read the BMW B48 powertrain guide and B48 ownership signals before viewing a car.

Compare evidence, not badges

For either engine, prioritize:

• A cold start you witness yourself
• Consistent invoices and oil-service dates
• A complete BMW-capable diagnostic scan
• Stable coolant level and operating temperature
• Smooth gearbox behavior
• Matching tires and predictable chassis behavior
• No unexplained warning-light history

One well-maintained B47 can be a better purchase than a neglected B48, and the reverse is equally true.

Simple decision

Choose the B47 when long journeys are genuinely routine and the emissions-system data is healthy. Choose the B48 when use is mixed, annual mileage is moderate, or short trips are unavoidable. In both cases, complete the pre-purchase checklist before discussing price.