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BMW's passenger cars come in three size classes, each offered with gasoline, plug-in hybrid, or fully electric power. Compare length, width, rear-seat room, trunk space, and powertrains side by side to build your shortlist before you research individual models or browse inventory.
Last reviewed: October 2026 | Specifications: 2026 model year, BMW USA
BMW's sedans fall into three pairs that share dimensions. The 3 Series and i4 are the compact class at about 186 to 189 inches long. The 5 Series and electric i5 are the midsize class at 199.2 inches, with noticeably more rear legroom. The 7 Series and electric i7 are the full-size flagships at 212.2 inches, with the most rear-seat space in the lineup. Trunk space grows only modestly between classes, so choose mainly on rear-seat room, exterior size, and powertrain. One note on shape: the i4 is a Gran Coupe with a liftback rather than a conventional sedan trunk.
Figures are for the 2026 model year. Width is body width excluding mirrors. Trunk volume is measured with all seats in place and can vary by powertrain.
| Model | Class & Body | Length x Width | Wheelbase | Seats | Trunk | Available Powertrains |
|---|---|---|---|---|---|---|
| 3 Series | Compact sport sedan | 185.9" x 71.9" | 112.2" | 5 | 17.0 cu ft | Gasoline 4-cylinder (330i, 330i xDrive); 6-cylinder with 48V mild-hybrid assist (M340i, M340i xDrive); BMW M (M3) |
| i4 | Compact electric Gran Coupe (liftback) | 188.5" x 72.9" | 112.4" | 5 | 16.6 cu ft (45.6 cu ft seats folded) | All-electric (eDrive40, xDrive40, M60) |
| 5 Series | Midsize executive sedan | 199.2" x 74.8" | 117.9" | 5 | 18.4 cu ft (530i) | Gasoline (530i, 530i xDrive, 540i xDrive); plug-in hybrid (550e xDrive); BMW M plug-in hybrid (M5) |
| i5 | Midsize electric sedan | 199.2" x 74.8" | 117.9" | 5 | 17.3 cu ft | All-electric (eDrive40, xDrive40, M60 xDrive) |
| 7 Series | Full-size flagship sedan | 212.2" x 76.8" | 126.6" | 5 | 19.1 cu ft (740i) | Gasoline 6-cylinder (740i, 740i xDrive); plug-in hybrid (750e xDrive); gasoline V8 (760i xDrive) |
| i7 | Full-size electric flagship | 212.2" x 76.8" | 126.6" | 5 | 17.7 cu ft | All-electric (eDrive50, xDrive60, M70 xDrive) |
The easiest BMWs to park and maneuver, with the 3 Series offering a traditional trunk and the electric i4 offering a liftback that opens to a much larger cargo area when the rear seats fold. A strong fit for commuters and drivers who mostly carry one or two passengers.
Identical exterior dimensions with a choice of gasoline, plug-in hybrid, or electric power. The 117.9-inch wheelbase gives rear passengers 37.0 inches of legroom in the 530i, making this the class to consider if adults regularly ride in back.
BMW's flagship sedans share a 126.6-inch wheelbase and offer 43.3 inches of rear legroom in the 740i. Choose this class when rear-seat comfort is the priority; the 7 Series also offers the largest trunk in this comparison.
Five of the six models in this guide are conventional sedans, with a separate trunk and a trunk lid that opens below the rear window. The i4 is a Gran Coupe: a four-door car with a sloping roofline and a liftback, where the rear glass lifts with the hatch. That gives the i4 a wider loading opening and a 40/20/40 folding rear seat that expands cargo space to 45.6 cubic feet, while trading some rear headroom for its lower roofline. Our Coupe, Gran Coupe, and Convertible guide explains these body styles in detail.
BMW's sedan lineup is changing generations, so the model year of a specific vehicle matters when you compare sizes:
Trunk volume ranges from 17.0 cubic feet in the 3 Series to 19.1 cubic feet in the 740i, a smaller gap than the jump in exterior size suggests. Moving up a class mostly buys rear-seat room and ride comfort. If cargo is your main need, also compare the i4's liftback or a model from our BMW SUV size guide.
Body width excludes mirrors. With mirrors, BMW lists widths of 81.4 inches for the 3 Series, 84.9 inches for the 5 Series, and 86.3 inches for the 7 Series. Measure your garage opening before choosing a midsize or full-size sedan.
Consider how each size class fits the way you drive around the Cape and beyond:
The 7 Series and the electric i7 are BMW's largest sedans. For the 2026 model year, both measure 212.2 inches long on a 126.6-inch wheelbase.
The i4 has four doors, but BMW builds it as a Gran Coupe with a sloping roof and a liftback rather than a conventional trunk. It offers 16.6 cubic feet of cargo space with the seats up and 45.6 cubic feet with the rear seats folded.
Yes. For the 2026 model year, the 5 Series and i5 share the same 199.2-inch length, 74.8-inch width, and 117.9-inch wheelbase. The main difference is the powertrain: the i5 is fully electric, while the 5 Series offers gasoline and plug-in hybrid versions. Trunk volume differs slightly, at 18.4 cubic feet for the 530i and 17.3 cubic feet for the i5.
BMW's current plug-in hybrid sedans are the 550e xDrive, the 750e xDrive, and the M5. A 3 Series plug-in hybrid is not part of the current U.S. lineup.
BMW's new electric compact sedan is the i3, which BMW positions as the successor to the i4. Ask our team about availability and how it compares with the gasoline 3 Series.
The 7 Series offers the most rear legroom in this comparison, with BMW listing 43.3 inches for the 740i, compared with 37.0 inches in the 530i.
Source: Dimensions, wheelbase, seating, legroom, mirror widths, and trims reflect 2026 model year BMW USA and BMW Group specifications. Trunk volumes for the 530i, i5, and 740i are BMW-published figures; 3 Series, i4, and i7 trunk volumes reflect published 2026 model year specification data. Figures can vary by trim, powertrain, and equipment, and 2027 model year vehicles may differ. Availability is subject to current inventory. Confirm specifications for any specific vehicle with BMW of Cape Cod.