Kia Sorento Plug-In Hybrid Sport Mode Long Distance Test: Inconclusive But Interesting

Even though my results were inconclusive, I will say this: the fact that the difference in fuel economy between my two trips, approximately a year apart, was apparently only .8 MPG suggests: 1. That the margin for error covers the difference and 2. The notion that a fellow Kia Sorento PHEV owner has put forth is not without merit. I call out this second point specifically because, while I still can’t say with 100% certainty that using the Kia’s Sport Mode results in worse MPG, I have done enough testing to say that at best, it’s a wash. Here are the details to explain why I say this.

I previously described the parameters for this trip, and that turned out as follows. I drove 6 miles from my home on battery power alone before switching the Sorento PHEV into Sport mode. We were at 85% charge and 25 miles of battery range remaining at that point. I drove in Sport Mode for the next 30 or so miles, until I was cresting the highest point of Snoqualmie Pass and began to coast downhill. After cresting the highest point, I toggled between EV mode and Sport mode on downhill sections (to capture a little more charge from coasting without the engine running) until we reached the first flat stretch beyond the pass. At that point, with the battery now recharged to 98% capacity, I kept the Kia in full EV mode and drove about 20 miles until the battery was down to about 40%. At that point I switched it back to Sport mode until the battery again reached nearly a full state of charge (99%), shortly after coming down the second mountain pass we had to cross (over Manastash and Umtanum Ridges). After driving for about 10 miles in EV mode, partly on a slower section of highway at 62 MPH, and the rest at about 70 MPH, I switched back to Sport Mode until we were 17 miles from our destination and used EV mode the rest of the drive, attempting to end the trip using up most of the battery (but not all, as I wanted to make sure I had at least a few miles left for local travel, later). We arrived at our first stop, Kiona Vineyards and Winery (excellent malbec and red blends), with 48% battery/11 miles of charge remaining and achieved 37.5 MPG (combined gas and electric) on our 203.2 mile drive. This was .8 MPG better than the trip we made last year, at 36.7MPG. The difference could be explained by small differences in the way I drove, the road conditions, whether there was a headwind, by the fact I did not have my roof racks on this time, etc. Technically I did manage to get slightly better gas mileage using Sport Mode and toggling to EV mode whenever the battery was nearly full. I don’t fully trust that my results are definitive. Using Eco Mode and keeping the vehicle in HEV mode mostly, as I did last time, I could just as easily have matched or beaten my figures this time. Perhaps I will retry the test the next time I come this way, but toggle Sport and EV modes more frequently, keeping the state of charge between about 40 and 80% to see if maybe that increases, or decreases my efficiency.

As one final set of details, that offer more proof for why I don’t fully trust my results, we continued our trip after making an hour-long stop at another winery a mile down the road, at Hamilton Cellars. This winery offers free 240V level 2 charging, powered by the sun, and we added 6 miles of range to our battery while sipping some delicious Merlot and Malbec, and chatting with some truly wonderful staff; thank you Hamilton Cellars! After we got back on the road, we drove another 71 miles, with about 12 of those miles at 71 MPH and most of the rest at 63 MPH. I kept the car in Eco and HEV Mode until we were about 17 miles from our destination before switching back to EV Mode, again to use up most of the battery before we arrived. We arrived with 4 miles of range left on the battery and a combined 40 MPG. We didn’t have any mountain passes on the last leg of our drive (to Walla Walla, Washington), and the average speed was a little lower, and that at least partially explains the better MPG figure. But it also reinforces the notion that Eco and HEV Modes can yield better results. More testing will hopefully settle this, eventually!

Please leave any questions or comments below.

Images courtesy of Justin Hart.

Justin Hart has owned and driven electric vehicles for over 15 years, including a first generation Nissan LEAF, second generation Chevy Volt, Tesla Model 3, an electric bicycle and most recently a Kia Sorento PHEV. He is also an avid SUP rider, poet, photographer and wine lover. He enjoys taking long EV and PHEV road trips to beautiful and serene places with the people he loves. Follow Justin on Twitter for daily KIA EV news coverage.