The 2019 BMW i3s with range extender achieves an EPA-estimated 31 MPG combined, a figure that highlights its core mission: providing efficient urban mobility with a standout, quirky design. It’s designed for navigating city streets with a minimal carbon footprint, and limited reliance on public charging.

City and highway performance

The EPA numbers reveal a very slight variation: 30 MPG in the city and 31 MPG on the highway. This near-equivalence indicates the i3s’ intended usage. The 0.6L two-cylinder range extender isn’t optimized for sustained high-speed cruising; it’s designed to kick in and maintain a usable charge when the battery depletes beyond a certain point. Its primary function is to prevent range anxiety, not to enhance performance on the open road. The i3s’ electric motor handles most of the propulsion, meaning that even at highway speeds, the efficiency remains relatively consistent with urban driving.

Annual fuel cost

The EPA estimates an annual fuel cost of $1,850 for the 2019 BMW i3s with range extender. This figure is based on driving 15,000 miles per year and using national average fuel prices for gasoline. This cost reflects the supplementary fuel consumption of the range extender and assumes it is used with some regularity throughout the year. If the i3s is primarily used for short trips with frequent charging, the actual fuel expenditure may be lower, however, the $1,850 figure provides a benchmark for understanding the overall expense of operating the vehicle, combining both electricity and gasoline costs.

Real-world expectations

While the EPA estimates provide a useful baseline, real-world MPG can vary significantly depending on driving style, environmental conditions, and the frequency of charging. Drivers who predominantly use the i3s for short commutes and plug in frequently can expect to use the range extender sparingly, and they will see far better overall fuel economy. On the other hand, those who frequently rely on the range extender for longer trips will experience MPG figures closer to the EPA estimate, or possibly even lower if driven aggressively. It is important to understand that the range extender adds weight and complexity, slightly compromising the overall efficiency compared to a purely electric vehicle.

How it compares

Compared to other vehicles in its class and price range, the 2019 i3s with range extender occupies a unique space. A fully electric vehicle like the Chevrolet Bolt EV offers significantly better overall efficiency because it avoids the use of any gasoline at all, achieving approximately 120 MPGe. However, the Bolt lacks the safety net of a range extender, making it less appealing to those who fear running out of charge. The Nissan LEAF, another popular EV, also provides better MPGe than the i3s with range extender. When considering conventional gasoline-powered vehicles, many compact cars achieve similar or better fuel economy on the highway, but few can match the i3s’ efficiency in city driving, where the electric motor excels. The Toyota Prius Prime, a plug-in hybrid, achieves an EPA rating of 54 MPG combined when running as a hybrid, making it a more efficient alternative for those who want both electric and gasoline power, but without the i3s’ distinctly avant-garde styling. See I3S MPG across all years to compare ratings per year.

Tips to maximize efficiency

One of the easiest ways to improve your fuel economy is to pre-condition the cabin while the i3s is plugged in. Using electricity from the grid to heat or cool the interior before departing saves battery power during the drive and reduces range extender usage.

Aggressive acceleration and braking consume significant energy. By adopting a smoother, more anticipatory driving style, you can maximize the regenerative braking system’s effectiveness and minimize the need for hard braking. This will extend the electric-only range and reduce the amount of gasoline the range extender uses.

Keep your tires properly inflated. Underinflated tires increase rolling resistance, forcing the electric motor and, eventually, the range extender to work harder. Check the tire pressure regularly and inflate to the recommended level specified on the door jamb.

Minimize the use of energy-intensive accessories. Running the air conditioning or heater at full blast, especially during the initial phase of a drive, drains the battery quickly and forces the range extender to activate sooner. Use these features carefully, and consider using the seat heaters instead of cabin heat, as seat heaters consume less power.

Plan your routes strategically to take advantage of regenerative braking. Routes with frequent stops and starts allow the regenerative braking system to recapture energy and extend the range. Avoid prolonged highway driving, where the range extender is more likely to engage. Browse all Bmw fuel economy data for more resources.