I’m a proud owner of a 2015 Bmw I8, which I purchased about six weeks ago. The car, with its striking Protonic Blue exterior and Giga Amido Black interior, had just over 30,000 miles on the clock when I got it. I’ve fallen in love with almost everything about this vehicle – its futuristic aesthetics, the exhilarating driving dynamics, and the surprising practicality of having rear seats that are just about perfect for kids.
My primary reason for choosing the i8 was to have a stylish and efficient daily commuter, aiming to eliminate gasoline usage for my work trips. My commute is roughly 6 miles each way, and while the i8 comfortably handles a single trip on electric power, the round trip is proving to be a bit more challenging than I anticipated, especially when workplace chargers are occupied.
Initially, I hoped for a fully electric round trip on most days. However, I’ve found the electric range to be right on the cusp. A full charge typically displays an estimated electric range of 12–13 miles, and in my experience, this estimate is quite accurate in predicting when the gasoline engine will kick in.
Take this morning, for example. After an overnight charge at home, I set off for work in Max eDrive mode with ECO PRO activated. Driving with a light foot and navigating through moderate city traffic, including a stop to drop my child at school, the battery level dropped from 100% to 50% in 24 minutes, covering 6.4 miles.
Alt text: Protonic Blue BMW i8 showcasing its sleek exterior design, illustrating the model mentioned in the article.
According to the trip computer, reset at the start of my journey, my electricity consumption was 2.5 miles per kWh (or 24.8 kWh/100km). This translates to 2.56 kWh used for 50% of the battery capacity, suggesting a total usable battery capacity of 5.12 kWh. This figure is quite close to the commonly cited 5.2 kWh of usable capacity for the i8’s battery, which is somewhat reassuring in terms of battery health. However, I’m aware that onboard fuel economy displays aren’t always perfectly accurate, sometimes deviating significantly from actual fuel consumption.
Over the past month, an average of 2.5 mi/kWh seems to be the norm for my commute. On particularly efficient days, I’ve managed to reach up to 3.0 mi/kWh by driving exceptionally gently and avoiding harsh braking and acceleration, and minimizing stops. Achieving this consistently is proving difficult, suggesting other variables like weather conditions might be at play. When I do achieve closer to 3 mi/kWh, the electric range does extend a bit further.
But here’s where my concerns really begin.
The EPA ratings on fueleconomy.gov for a 2015 BMW i8 state an all-electric range of “0–14 miles.” My current 12–13 miles isn’t drastically off, but the EPA also lists a consumption figure of “43 kWh/100mi”. This equates to 2.32 mi/kWh. Given that I’m consistently achieving 2.5 mi/kWh or better, I would expect a range closer to 15 miles, or even 18 miles on those more efficient days reaching 3.0 mi/kWh. This isn’t the range I’m experiencing.
Moreover, the EPA figures imply a usable battery capacity of (43 kWh/100mi * 14 miles / 100 miles) = 6.02 kWh. If the widely accepted 5.2 kWh figure is correct, or even considering my calculated 5.12 kWh, there’s a discrepancy. Either the EPA figures are inaccurate, or my battery might be operating at around 15% less capacity than it should, assuming the 5.2 kWh figure is indeed the correct one.
I’ve also noticed inconsistencies during charging. This morning, recharging the battery from 50% back to 100% using a commercial ChargePoint unit, the charger reported delivering 3.28 kWh. If my trip computer’s consumption figure of 2.56 kWh for that 50% depletion is accurate, this suggests a charging efficiency of only around 78%, which seems rather low.
Alt text: Luxurious Giga Amido Black interior of a BMW i8, highlighting the sophisticated cabin and the car’s premium features.
My worry stems from range issues I encountered shortly after purchasing the car. Initially, the displayed and actual all-electric range was only 8–10 miles. I took the i8 to my local BMW dealership. They diagnosed a fault with the “low voltage battery” causing excessive power drain and subsequently replaced it. I believe this was simply the 12V battery, which, strangely, they had to ship across the country, resulting in a two-week wait for the repair. They assured me everything else was in good order, and indeed, the range improved to the current 12–13 miles after this service. However, I remain concerned that there might still be an underlying issue affecting the battery performance.
Browsing online forums and internet reviews, I’ve come across anecdotal reports of BMW i8 owners achieving 20–25 miles of electric range. With my current experience, these figures seem unattainable regardless of driving style or conditions. Is my 12–13 miles of all-electric range typical for a 2015 BMW i8, or should I schedule another visit to the dealership to investigate potential further issues with the hybrid system or battery? Any insights or shared experiences from other BMW i8 owners would be greatly appreciated.
