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Why Kia Makes A Better Plug-In Hybrid Than Chevy Did

I’ve owned two plug-in hybrids (PHEVs). They are fascinating vehicles. Though they are not the same class (one: the compact 5 door liftback Chevy Volt, the other: the 3 row midsize Kia Sorento SUV), as PHEVs they both could run in electric only mode for significant distances and consume far less gasoline than equivalent gasoline only vehicles. My two PHEVs behaved differently when driven and while I definitely prefer how Chevy implemented its electric drive mode, I believe that Kia has made a more effective PHEV.


Now, I don’t mean to hurt anyone’s feelings (because owners of the Chevy Volt tend to be a die hard bunch), and as I said I much prefer how Chevy implemented its EV mode in the Volt, but when I consider each vehicle as a whole, their efficiency, their handling and performance in both electric and hybrid modes, or basically their function as PHEVs, I feel like Kia did a little better job with the Sorento PHEV. Here’s my reasons why I think Kia edges Chevy out with their respective PHEVs.

First and foremost, Kia made a more efficient PHEV in the Sorento. How is this possible, you may ask, when my “gen 2” 2017 Volt has an MPGe of 106 and my Sorento PHEV only has an MPGe value of 79? My Sorento PHEV weighs about 1,000 lbs (or 29%) more than my Chevy Volt. It is also much larger and less aerodynamically efficient, yet I am able to get about 90% of the miles per kWh figure I got in my Volt (3.6 lifetime over 4 and a half years), in my Kia (3.24). That means I can go 90% as far on the same amount of electricity, basically, but am moving 29% more weight every time I do. I drove both vehicles in a similarly gentle way because in a PHEV my goal is to maximize the distance I cover in electric only mode. But the Kia Sorento PHEV is more efficient in another important way too: its use of raw materials. The Sorento PHEV has a 13.8 kWh battery, the 2017 Volt has an 18.4 kWh battery (so the Volt’s battery is 25% greater capacity), That means that Kia’s PHEV, “pound for pound”, is doing more with less since the Chevy Volt used 25% more battery (4.6 kWh worth) to achieve only a 10% better result in its vehicles consumption of electricity in my real world driving results. I believe I know why this is the case: Chevy could tap its hybrid battery for cabin heat whereas Kia can not. Kia may also just have designed a slightly more efficient electric motor or transmission, too (though that’s just a guess on my part). This may not sound like much, and I certainly did like being able to heat my Volt without using gas, but once I researched Kia’s approach a little I have come to appreciate that using a battery for cabin heat is actually pretty inefficient. Perhaps if a heat pump were used instead of a resistance heater, that wouldn’t be the case, but that isn’t what Chevy (or Kia) did.

Next, Kia’s PHEV handles better when running in hybrid mode. Specifically, I mean that when the gas engine is operating in the Kia, I don’t experience some of the characteristics the Volt displayed when running its gas engine. The Volt would “throb” subtly when driving at freeway speeds when in hybrid mode and the gas engine RPM was disconnected from the speed of the vehicle. While I usually had adequate power in hybrid mode, there were some times (when trying to pass a slower moving vehicle for example) that the Volt just felt like it was struggling a bit. In short, the Volt was a great EV, but as a hybrid it felt buzzy, a little bit sluggish at times, and had some unpleasant vibration from the gas engine. The Kia Sorento, with a similarly sized gas engine, feels relatively smooth, more powerful, with seamless integration between the electric motor and gas engine in hybrid mode. I’ll also just point out, even though it is obvious, that the Kia is a much more versatile vehicle (being a midsize SUV), and that is no fault of the Volt itself, being a different class of vehicle, but it is a fault of Chevy (they should have put the powertrain in a more versatile chassis, like it’s Equinox perhaps).

Before Volt fans tar and feather me, I’d like to point out what I think Chevy did better in the Volt than Kia does in the Sorento PHEV. First, as I mentioned above, the EV mode in the Volt is just a better experience and more useful overall because no matter how far you press the accelerator down, the Volt stays in EV mode until you switch it out or the charge is used up. There are engineering and mechanical reasons why this isn’t the case in the Sorento PHEV, but still, the Volt was just a better experience because of this feature or design. And although this isn’t related to these vehicles' performance, the other feature I very much appreciate in the Volt and wish Kia would fix is an aspect of their infotainment system. In the Volt, I could use Apple Car play for GPS while listening to any other audio source available in the car (so bluetooth from a phone, music coming in from a USB port, the radio (FM/AM or XM), etc.). Technically I am able to get the FM/AM and XM radio to play when I am using Apple Car Play for GPS in my Sorento, but it makes no sense at all and only works when I have the forethought to leave the head unit on the desired audio source before I turn off the car knowing that I will plug my phone in to use the GPS next time I drive. Something seems to be messed up in Kia’s operating system running on its head unit (or just poorly designed). I also seem to have far more issues with Car Play than I ever did in my Volt (though to be fair, that could just be due to my phone or the cable I am using, something I’ll have to test in other vehicles or with other cables).

Have you driven both PHEVs, or perhaps other Kia PHEVs? Would you agree with my assessments, or do feel otherwise? Please leave your questions and 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.


Greg (not verified)    January 26, 2023 - 9:18PM

I just purchased a 2023 Sportage PHEV. Obviously the same drivetrain as the Sorento PHEV, but in a slightly smaller and lighter package. I am only in my first week of ownership, but I am truly impressed with just how good this PHEV system is. I actually traded my unicorn Ford Maverick Hybrid in on the sportage. The Maverick Hybrid is amazing for the money, but it just wasn't exactly what I needed. I too was a fan of both generations of the Volt. GM never ceases to amaze me when it comes to leading in innovation and then being unable to properly market something or simply failing to pivot and put the technology in a platform people want.

Justin Hart    January 27, 2023 - 5:33AM

In reply to by Greg (not verified)

You can say that again! I wonder if the Sportage, being a little bit lighter than the Sorento, might actually have a little bit “deeper” travel on the accelerator before the gas engine kicks in. How far down would you estimate you can push the accelerator before the gas engine kicks on, Greg? Thanks for the comment, and enjoy that Sportage PHEV!

Greg (not verified)    February 21, 2023 - 4:41PM


I am a little over 4 weeks in to my ownership of the Sportage PHEV. Still a fantastic vehicle so far. I finally got my Level 2 charger in my garage last week, so full charges in just under 2 hours is really nice compared to 10-11 hours with the supplied Level 1 portable charger included.

Since I took delivery a few weeks ago, almost all of my miles have been driving in ECO mode, full EV, with engine running only for heat. I am still on the second tank of fuel, a bit less than a quarter of a tank left. The first tank was the fill-up from the dealer, and I used that tank up getting the vehicle home from Pittsburgh. I used the first quarter of the second(current) tank on the journey home from the dealer as well.

Here is what I am getting from my data so far; for every 100 miles I travel in EV mode with the engine only running to provide heat, I am seeing a loss of 25 miles of gasoline range. Outside temps averaging 35-45 F, HVAC set to 70 F, vehicle garaged at night, parked in the cold at work, downhill to work, uphill on the way home, all city driving at 35-40 MPH average. Drive time for that 100 miles is about 200 minutes. That gasoline usage seems high to me, but I definitely need to track across more tanks of fuel. Of course, temperatures are slowly getting warmer as we approach spring, so variables are changing.

Justin Hart    February 23, 2023 - 2:38AM

In reply to by Greg (not verified)

Greg, you are driving in fairly similar conditions to me (in the Seattle area), though perhaps you’re trending a little bit colder (we’re more likely in the 40-50F range, at least this winter). What I would say is this: the gas “range” is always an estimate based on recent driving patterns. Since it sounds like you are doing slower speed driving, but perhaps with some idling time in there (in traffic?) you might be burning more gas due to traffic (compared to if you had no traffic and could just drive 45 MPH the whole way). If it is possible to estimate how much gas you are burning on each leg (there are 4 “quadrants” of the fuel tank on the gauge, and each is a little less than 3 gallons of gas) you might use that to guide your calculation of what your efficiency is in addition to what the gauges are telling you. Or, use the pump (i.e. put 5-6 gallons of gas in, track the miles until you use up 5-6 gallons… since it sounds like a full tank might last you all winter if all you are doing is commuting to and from work).

Anyway, what I find in the Seattle area is I burn about .1 (one tenth) of a gallon every 5-10 miles if I am just idling the engine for heat (or because I accidentally applied to much pressure to the go pedal and the engine has to run for a bit as a result) on my Sorento PHEV. The Sportage may be more efficient being smaller, but I feel like a really rough estimate is that the Sorento PHEV gets between 50 and 100 MPG when idling the engine for heat/because I pushed the accelerator down too much. This tracks to the times I have been able to measure my MPG during heater only use (usually a number between those figures). I imagine this would then lower the longer the trip (once I surpass the range of the battery, it would rather quickly drop into the 30’s MPG because of course I am in hybrid mode at that point). If you find that you are getting significantly less than about 50 miles per gallon when using gas for heat, consider whether you were stuck in traffic or if other circumstances may have forced the number lower (and if so, perhaps you could turn off the heat for awhile and just use heated seats/wheel, if you want the efficiency figures to improve). Once it warms up and you don’t need the heat anymore, you’ll definitely see much better results though. Pleas share whatever your findings are, regardless. :)

Greg (not verified)    March 1, 2023 - 2:29PM

Justin, I just filled up the tank again a couple of days ago. My hand-calculation of the actual MPG of the full tank was 77.18 MPG. I then backed out the first 55 miles on that tank since that was in HEV mode getting it home from the dealer with zero EV range. The calculation for that last 3/4 of a tank landed at 93.3 MPG. That 3/4 of a tank traveling 662 miles was at best-case scenario mild winter all city driving. If someone had one of these in a colder climate and had to park it outside at night, the numbers would be totally different. Once it warms up, I should be using hardly any gas in my commute and around town.

Justin Hart    March 3, 2023 - 2:28PM

In reply to by Greg (not verified)

That all sounds right to me! In the “mildly cold” Seattle winter (temps in the 30’s F) lately, when I have needed to use the cabin heat I was actually getting over 100 MPG on the dash display, though these were only for shorter drives of less than 15 miles and I had enough charge in the battery for most of the distance to otherwise be driving in EV mode. It just reiterates, if you do not have to run the engine for propulsion, just for heat, you’ll get significantly better mileage figures. Of course the colder it is the more you have to run the engine for heat and thus the worse your fuel economy will be. Even if we had electric heating units in our Kia PHEVs that drew from the hybrid drive battery, the impact on our EV only range during winter would be significant if using it for heat (would cut it by 1/4 - 1/2, I expect, depending on how cold it was out). Cheers!

Greg (not verified)    April 17, 2023 - 10:06AM

Reporting back in after a long trip in the Sportage PHEV. Unfortunately my early findings were reinforced. When this thing is running in hybrid mode once you use up the EV range on the interstate at around 75 MPH in Eco mode, I am still seeing 26-27 MPG. That is pretty sad MPG. I think to get 30-31 MPG, you will need to keep it at 70 MPH max. I ended up at around 31 MPG for the whole 600 mile or so trip. That was with a full charge at the start and a couple of full charges at our B&B at midpoint. Still not great considering the charging I was able to do. I am still really happy with the vehicle for my uses since 90% of my driving will be EV only, but really feel it should do a lot better than 26-27 MPG at my normal highway speeds. Perhaps things will improve as I get more miles on it.

Justin Hart    April 17, 2023 - 12:58PM

In reply to by Greg (not verified)

It is possible your gas engine is still being “broken in”, but definitely, driving a little slower will get you better mpgs. I wrote about this fairly extensive in this article and the two it links to that precede it:

I suggest, at your next opportunity for a long trip try these two things and see if it makes a significant difference: 1. drive the speed limit, or even a little below (try not using the cruise control if you’re up for it as I think it tends to rev the engine harder going up hills than may be necessary) 2. don’t use up all your EV range at the start of your drive (if you haven’t tried that already) and instead save at least several miles of range until you are getting close to your next charging opportunity (and then you can use their rest of the EV range up). Having more juice in the battery than the minimum can allow the gas engine to take a break more often and that might help improve your mpgs). Good luck and keep us posted! Oh, and just curious, do you have anything (racks, cargo box etc.) on the roof, are you using snow tires and what is your PSI at? Just a few other things that can have small impacts on your mileage…

Greg (not verified)    April 21, 2023 - 11:04AM

No racks, snow tires, cargo box. I need to experiment more with using Smart Mode or switch to HEV on the highway instead of ECO all the time. I do notice on the highway that Smart Mode uses the ICE a little more often when there is still EV range, but I think that is simply because it is set to be more responsive to power needs, not necessarily more efficient. Honestly, ECO should be the best for all scenarios.

Justin Hart    April 28, 2023 - 3:39AM

In reply to by Greg (not verified)

Hi Greg! Yes, definitely experiment with the drive modes and settings to see if you can find better ways to achieve your efficiency, or performance, goals. If Smart mode ends up being more efficient, let us know! I switch to HEV mode on the highway after a few miles (if I am starting with a full tank) and then just try to make sure I use up the remainder of the charge just before arriving at my next charging location.

Greg (not verified)    June 13, 2023 - 10:31AM

Update from a trip in the middle of May. A 330 mile or so trip this weekend showed some promising data. One section of the trip we did about 55 miles in hybrid mode due to already using up the EV range. That section was mainly at about 62 MPH on two-lane highways. Result was 32 MPG according to the trip computer. At the end of the trip we did another 55 mile section in hybrid mode, but this was on the interstate at between 72 and 74 MPH. The result was almost 33 MPG. That surprised me since before I had always seen around 26-27 MPG at interstate speeds. Not sure what was at play there. 3000 miles on the car, warmer temperatures now, potentially a slight downhill grade from Dayton to Cincinnati, who knows. Glad to see it though. I will keep tracking the numbers! Forgot to add that I was also testing the EV range on the interstate and I was surprised as well that it was able to go almost the entire stated 34 mile range at 72-74 MPH. I think it switched to HEV mode right around 30 miles of full EV in ECO mode.

Justin Hart    June 16, 2023 - 4:12AM

In reply to by Greg (not verified)

That is great to hear Greg! I am pleased to see you are getting results, now, that are closer to what you expected. It may have something to do with the “break in” period, or maybe you had a strong head or tail wind, or other such environmental variable (to cause the unexpected differences). What matters is you are starting to see better results. Happy motoring, and keep sharing your findings!