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Kia Sorento Plug-in Hybrid Fuel Cost Per Mile Revised: After Road Trips

Back in March, before I got a busted window replaced in my Kia Sorento plug-in hybrid (PHEV), I hadn’t taken many long drives and as a result had a stellar per mile fuel cost for the first 1,000 or so miles I drove. That cost was 5 cents per mile combined (gas and electric). But now I have taken multiple long road trips and it's time to update my figures.


Since I wrote about my per mile cost in late March, I have driven a little over 2,500 miles in our Sorento PHEV, primarily on 3 different road trips to the Oregon Coast, Washington wine country, and to a resort in sunny eastern Oregon. Because the distances involved on these trips (the two longer trips were both close to 1,000 miles total), a majority of the miles we put on the vehicle were in hybrid mode, which means we were using gasoline. On all of the trips I was able to plug in at some of the places we stayed or visited and do a good portion of our local miles on battery only, but following those 3 road trips our per mile fuel costs changed, as we might expect. Here’s how they changed, and note I use an estimated average price for gas based on what we pay at fill ups, but of course that’s just an estimate and includes some best guesses (my margin for error is 5% or so).

First, before we started taking road trips, more than 70% of our miles driven were on electricity, mostly on trips of less than 40 miles. After adding over 2,500 miles, mostly from long highway drives on the road trips, our electric only percentage dropped to a little over 46%. We used almost 43 gallons of gas in the last two months (April and May). I estimated the average gasoline cost per mile for these two months to be $4.67 per gallon based on my notes at each of our stops for gas. This means we have an estimated total gas cost of $200.81 for these 2 months. My calculated cost of gas per mile was about 12.5 cents for the last two months. My calculated cost of electric only miles (including the approximately 100 kWh of free, to us, electricity we got while on our trips at the same 9 cent per kWh price we would have paid at home) was just a hair over 3 cents per mile. If I didn’t count the free kWh, our actual electric per mile price would have been less than 3 cents. By blending gas and electricity per mile costs together, at present we are seeing a per mile fuel cost of around 8 cents per mile (up 60% compared to March, before we started taking longer trips).

Of course, our electric only percentage will start to creep back up as soon as we take a break from longer trips that greatly exceed the 34-40 miles of battery only range we have been getting, per charge. If I were to include our June driving to date, and estimate what the rest of our month’s usage would look like, our cumulative percentage of electric only miles would already be back around 50%. We’ll likely take a couple more longer drives over the summer, but by the time fall rolls around, we may not drive more than 50-100 miles in our PHEV on any given day for several months in a row, or at least rarely do so until sometime next year. That may get our electric only percentage back into the 70% neighborhood by the end of the year, depending. That would also mean our blended cost per mile will also go back down, though the average price of gas staying high may prevent that from getting back to 5 cents per mile. I am estimating it will be more like 6 cents per mile unless gas prices significantly improve or we don’t end up taking our Kia on any road trips longer than 100 miles for the rest of the year. That’s still excellent, if it turns out to be true. For sake of additional comparison, if I had been driving the Kia Sorento Hybrid which doesn’t plug in and gets an EPA estimated 37 mpg combined, my per mile fuel costs would be approximately double what I predict I may end up with toward the end of this year in our Sorento PHEV.

Do you tend to drive like I do, with a handful of long highway trips at certain times of the year but otherwise doing a majority of your miles on shorter drives of 50 miles or less? If so, you may be the kind of driver PHEVs are best suited for. If not, might you choose a hybrid or EV instead? Leave your questions or comments below.

Image courtesy of Justin Hart

Justin Hart has owned and driven electric vehicles for over 14 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.


Mike (not verified)    September 14, 2022 - 3:33PM

Got our Kia Sorento PHEV in October 2022 and have 8,000 miles in it now. Overall I love it. I Try to only drive on electric except for long trips. During the summer I am thrilled the AC runs on the battery and doesn’t seem to depress electric driving mileage that I can tell. But it is very frustrating that in winter if I turn on the heat it turns on the gas engine and seems to run down both electric battery and result in poor gas mileage like 35 mpg. Is there any way to use the electric battery to generate heat instead of having the gas engine turn on? I heard perhaps teslas have heat pumps which would have addressed this. Only thing I found to avoid this is not turn on heat, or only use the battery powered heated seats. Also the computer says I am averaging 85 mpg lifetime for these 8,000 miles so I’ve used about 100 gallons of gas in nearly 12 months.

Justin Hart    September 16, 2022 - 1:09PM

In reply to by Mike (not verified)

Hi Mike! Sounds like your doing a great job at making the most of your Sorento PHEV’s battery, keep it up! To speak to your question, as both a Kia Sorento PHEV owner and a Tesla owner (though my Tesla is a 2018 model, before they started using heat pumps) I can speak to your question with some knowledge and experience. Unfortunately, for those of us that would rather not have the gas engine run to produce cabin heat, we’re out of luck when it comes to Kia’s PHEVs and actually for most hybrids of any type (though my Chevy Volt was one such PHEV that DOES have an electric resistance heater and could heat the cabin without running the gas engine… but could also use the heat from the gas engine when it was running, too). So no, Kia and most other brands intentionally do not have electric heaters in their hybrids/plug-in hybrids (either resistance heaters OR heat pumps) and in short the reason is because it adds expense and weight to the car (in addition to the extra parts, the battery’s thermal management system needs to be more robust to handle the additional draw, and the battery itself needs to be larger capacity to maintain the stated range since even heat pumps will use up 10-15% of your range on a winter’s day). So, from an efficiency perspective and or from the perspective of making more PHEVs with the available battery supplies, Kia’s choice makes sense. I don’t like burning gas either, just to stay warm, so here are things I do to try and minimize my use of the gas engine for heat: 1. dress warmly (of course!) 2. use the heated steering wheel if you the option 3. try experimenting with the drive modes; if you know you are going to drive beyond the range of the battery anyway, maybe run the HEV or Sport mode first, to get the engine warm quickly (instead of just idling it as it does when you turn on the heat but are otherwise in EV mode). The PHEV may be able to run the heat for sometime/not idle the engine for a time once you switch it back to EV mode. You would still be burning gas of course, but you may use less/get better MPGs.

Teslas don’t have gas engines, of course, so they all use electric heating solutions, either restive heaters or heat pumps (in the newer models). But as I mentioned above, both use up battery charge, and resistive heaters can use as much as 20-25% of your range on a long drive in the winter, depending on how cold it is. Some other things you could consider: get an electric blanket that plugs into your 12V outlet in your Kia (but make sure it doesn’t draw more power than the 12V outlet can support!), or a very small space heater (I have one that can run at 150 watts for example, on at least the rear 12V outlet in the Sorento PHEV, that heater could be run). Those might not be very practical solutions of course, but technically they could keep you warmer. Ultimately what I suggest is to accept that you’ll need to use some gas in the winter for heat, and just do what is reasonable, to you, to minimize what you use. If you end up owning a full EV at some point, you’ll get that electric heat (or if you buy certain PHEVs), but I hope you don’t feel you need to get rid of your Sorento PHEV because of this design choice Kia very intentionally made. We shouldn’t let perfect be the enemy of the good.