Roughly speaking, the 645Ci is quick for a mid-2000s luxury grand tourer, with 0–60 mph times in the mid to upper 5-second range and a governed top speed around 155 mph. By modern standards, it’s not a true sports car, but it delivers solid, refined acceleration and a smooth V8 soundtrack that suits its GT purpose.
Performance snapshot
This section highlights the core numbers that define the 645Ci’s speed, power, and handling characteristics.
Engine and drivetrain basics
- Engine: 4.4-liter V8 (N62B44)
- Power: about 325–333 horsepower, depending on year and market
- Torque: around 251 lb-ft (340 Nm)
- Transmission: 6-speed manual or 6-speed automatic
- Drive: rear-wheel drive
- 0–60 mph: typically about 5.7–6.0 seconds
- Top speed: electronically limited to 155 mph
- Weight: roughly 3,900 pounds (varies by build and options)
In daily driving, the car emphasizes smooth, confident acceleration and a relaxed GT demeanor rather than razor-sharp, track-focused speed.
Real-world performance and driving experience
On the road, the 645Ci rewards elegant, effortless acceleration and a refined, spacious cabin. Its throttle is progressive, the V8 sound is prominent without being intrusive, and the car emphasizes comfort, long-distance usability, and a composed ride. The heft of the chassis means it doesn’t feel as nimble as a modern performance coupe, but it remains capable and satisfying for highway merging, overtaking, and spirited cruising.
Buying a used 645Ci: quick checklist
Before buying a used 645Ci, use these checks to gauge condition, history, and ongoing costs.
Key checks
- Comprehensive service history, including major maintenance and any VANOS/valve-train work
- Cooling system condition: water pump, thermostat, radiator, hoses, and coolant leaks
- Timing-chain/valvetrain reliability and any signs of excessive wear
- Transmission condition: smooth shifting (manual) or reliable automatic operation
- Electrical systems and interior electronics: gauges, climate control, iDrive functionality
- Body integrity and rust, especially around wheel arches and undercarriage
These checks help identify cars that have been properly maintained versus ones that may require costly repairs soon.
Ownership outlook and verdict
Owning a well-kept 645Ci can be a rewarding experience for buyers who value a grand-touring vibe, V8 character, and classic styling. Be prepared for maintenance costs associated with an aging European luxury car, including cooling-system components, suspension wear, and electronics. Budget for routine service and potential repairs, and consider a pre-purchase inspection from a BMW specialist to uncover issues early.
Summary
The 645Ci offers respectable performance for its era, with a smooth and charismatic V8 and a comfortable grand-tourer drive. It won’t outpace modern sports cars, but for enthusiasts who value refinement, sound, and road presence, a well-maintained 645Ci remains a compelling choice. Prospective buyers should weigh upkeep costs against the pleasure of the car’s character and style, and pursue thorough inspections to ensure reliability.