BMW G11/G12 (2015–2019): A Quick Breakdown of the Flagship Sedan
Quick summary. The G11/G12 BMW 7 Series is a flagship with a Carbon Core body that weighs 287 pounds less than its predecessor while being stiffer. Your best bet is the 730d diesel (B57) for high mileage, or the gasoline 740i (B58) if reliability tops your list. The pre-2019 V8 is a gamble. The big-ticket items are the EGR valve, air suspension, and Run-flat tires.
The Problem: A Flagship with Character
You climb into a luxury sedan, and around 37,000–50,000 miles the first surprises start. The diesel loses power, the suspension thuds over bumps, and the service bills keep growing. The BMW G11/G12 is a tech-heavy car that rewards a deliberate approach to buying and maintenance. That goes double for the diesel versions with their EGR valve and the complex V8s built before the 2019 facelift.
Symptoms of Common Failures
- Power loss and rising fuel consumption on the diesels
- Suspension thudding and strange noises over bumps
- Electronics glitches: infotainment, sensors, control modules
- Oil leaks and turbo noise on the pre-2019 V8s
- Uneven wear on the Run-flat tires
- EGR valve faults on the B57
The Causes: Why It Happens
The EGR valve on the B57 diesels is the most frequent problem. The exhaust gas recirculation system cokes up with carbon, cutting power and pushing fuel consumption up. Many cars were covered by a recall campaign, but not every owner went through with it. A failed valve can end in engine damage.
Air suspension on both axles wears out over time: the compressor, the valve block, or the air springs can fail. Electronics on early builds act up, and Run-flat tires cost more than conventional rubber and wear out faster.
The Fix: How to Choose and Maintain
Choosing an Engine
| Engine | Versions | Fuel Economy | Longevity | Reliability |
|---|---|---|---|---|
| B57 (diesel, inline-six) | 730d, 740d, 750d | 33–39 mpg | 186,000–249,000 miles | High with the EGR valve kept in check |
| B58 (gasoline, inline-six) | 740i | 20–24 mpg | 155,000–186,000 miles | The best in the lineup |
| V8 | 750i | — | — | Low before 2019 |
The 730d (B57) is the pick for high-mileage drivers: frugal, with strong pull down low. The 740i (B58) is the most reliable engine in the lineup — 0–60 mph in 5.5 seconds, with no EGR or diesel particulate filter to worry about. The pre-2019 V8 brings frequent oil leaks, turbo trouble, and timing chain issues, and the repairs are expensive.
Maintenance
- Confirm the EGR recall campaign was completed on the 730d — your dealer can check by VIN.
- Clean the intake manifold on the diesels every 37,000–50,000 miles — carbon buildup saps power.
- Change the oil every 6,000–9,000 miles, and use only genuine or BMW-approved oils.
- Inspect the air suspension at every service — replacing the air springs on time will save the compressor.
- Steer clear of a 750d without a warranty — the complex four-turbo engine means expensive repairs.
Pre-Purchase Checklist
- [ ] Request a VIN report from an authorized BMW dealer
- [ ] Confirm all recall campaigns were completed
- [ ] Evaluate the air suspension on your test drive
- [ ] Check the electronics: climate control, infotainment, cruise control
- [ ] Inspect the body: the Carbon Core should show no cracks or chips
- [ ] Budget for substantial first-service costs and possible repairs
- [ ] Factor in the significant cost of a full set of Run-flat tires
The Bottom Line
The BMW G11/G12 is a car that demands a careful approach. The practical pick is the 730d (B57) with the EGR valve monitored and maintenance kept current. The safest bet is the 740i (B58). The 2019 facelift brought technical improvements but a polarizing design. Don’t skimp on the pre-purchase inspection, and this flagship will keep delivering comfort for years.