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As An EV, Kia’s Sorento Plug-In Hybrid Is Probably A Little More Efficient Than Toyota’s Rav 4 Prime

It recently occurred to me, after my neighbor bought a Toyota Rav 4 Prime plug-in hybrid (PHEV), to research certain differences (mainly in efficiency and performance) between it and my Kia Sorento PHEV. This has led me to a somewhat surprising supposition: I think the larger and heavier Sorento PHEV is a little more efficient, on battery power, than the Rav 4 Prime (note: the Toyota gets 4 mpg better, combined, on gas).

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Let’s look at the facts first. The Kia Sorento PHEV weighs about 250 - 300 pounds more than the Rav 4 Prime. But more importantly, it is 8 inches longer and 2 inches wider (and essentially the same height). The Sorento PHEV has less distance between its underbelly and the ground, at 6.9 inches of ground clearance, to Toyota’s 8.4 inches. That ground clearance may be equally as important to the overall efficiency as the other measurements I listed. Taken together, these may explain a slight Kia advantage, but it may also be due in part to other factors like the efficiency of the respective electric motors, the types of tires each uses, aerodynamics, etc. These are all possible factors that one could study with the right tools (tools which I lack). So I am going to somewhat crudely compare the EPA rated ranges and estimated usable battery capacities of each, as well as some real world user reported data, to narrow in on what I think the difference in electric powered efficiency is, however small it may be.

The Rav 4 Prime is rated in the US by the EPA for 42 miles of battery only range. I recently surveyed several Rav 4 Prime drivers on social media too for some context, and they reported ranges of between 32 and 77 miles on a full charge. The 77 mile claim came with the clarification that it was mostly downhill, on back roads and in warm temps so it is certainly a fringe case. The Rav 4 Prime has an 18.1 kWh battery, of which perhaps 14.5 kWh is usable (or a little more, depending; I saw some one claim of 14.9 kWh). The Sorento has a 13.8 kWh battery, of which 11.8 kWh is estimated to be usable.

Let’s plug in some real world figures for each, too. I have driven my Kia Sorento PHEV about 9,000 miles so far, and my lifetime miles per kWh figure is about 3.2. That means I am averaging around 38 miles of range per full charge, over time. The longest I have driven on a single charge was about 43 miles, or about 34% more than the EPA rated range and the shortest range I have gotten in less than ideal conditions is about 29 miles (happened once in cold, wet weather, with snow tires mounted, a completely full car, roof racks on and mostly highway driving), or about 10% less than the stated range. I also surveyed other Sorento PHEV drivers on social media to see what their best range on a full charge was. 49 miles was the highest and would be about 53% more than the EPA rated range. That was on a trip done on backroads at 40-50 mph, on flat ground, with no need for air conditioning (not quite as ideal as the 77 mile scenario the one Rav 4 Prime driver had, but still quite good). I mention all these user reported figures because I think it matters that people know it is possible to significantly exceed the range and efficiency figures the EPA provides, or to do worse (as a few people called out for both models), depending on how you drive it and what the conditions are. If we stick to the EPA ranges and full battery sizes as in the third paragraph, the two PHEVs have miles per kWh figures within a tenth of a mile, or two, of each other (2.8 - 2.9 miles per kWh for the Rav 4 Prime and 2.7 for the Sorento PHEV). Given that the Kia is about 4% longer, 3% wider, and 6% heavier though, the Kia seems as if it could be a little more efficient, on paper, since they have nearly the same range per kWh. Of course it does all come down to how one drives, and in what conditions. Also of concern: how easy is it to achieve the best efficiency? The Toyota is geared toward more straight line power, and it has the larger battery and more powerful electric drive motor so it may be harder (or easier) to keep it in the most efficient range.

I realize I am, at best, splitting hairs. But what do you think? Does the Kia impress you as much or more than the Toyota? Please leave your comments and questions below.

Images courtesy of Toyota and 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.

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Comments

geemy (not verified)    April 1, 2023 - 10:48AM

Sorento is about 5% bigger and heavier, RAV4 prime has double the electric power, 19% more efficient on electricity , 12% more efficient on gas.
it has eAWD, is 2.2s quicker to 0-60...
EPA move rating is based on the miles divided by that actual charge put into the other/ev so it's pretty accurate and less biased than people driving and reporting their range
Kia has other advantages like 3rd row or 5/10 years warranty
Toyota legendary reliability, and well proven hybrid technology with eCVT. some will always prefer an automatic but for an hybrid eCVT beats automatic on numbers, by every aspect.
Sorento has a slightly better drag coefficient at .32 vs .35, although worse than the previous gen 0.30 Sorento and rav4
Toyota tried to make the RAV4 more SUV/rugged while the venza takes the more crossover/refined niche

Justin Hart    April 5, 2023 - 5:46AM

In reply to by geemy (not verified)

That’s what I did to come up with the numbers for efficiency (miles per kWH, dividing the usable battery capacity by the EPA range). Given the extra weight and size of the Sorento, that’s why I say it is likely a little more efficient (their miles per kWh are very close otherwise). I have noticed and read a higher rate of failure/issues for the Rav 4 Prime than almost any other Toyota, interestingly, it is definitely not living up to the legendary Toyota quality that I agree is expected with most vehicles they make. I’d say the frequency of issues is similar to the Kia Sorento (in terms of users reported issues on social media, which I realize isn’t all that precise). Curious why you say eCVT beats automatic on numbers? Are you referring to efficiency? That may be debatable when we are talking about electrified vehicles vs. ICEs.

Fred (not verified)    April 2, 2023 - 10:21AM

I have read many of your PHEV articles and agree with many of your conclusions. One question I have is how do you determine that your "lifetime miles per kWh figure is about 3.2" for your Sorento PHEV? 3.2 mi/kWh is equivalent to 108 MPGe, which is 36% higher than the EPA rating of 79 MPGe for your Sorento PHEV. I am an engineer by training and tend to be skeptical when there is a discrepancy this large. EPA ratings usually overpredict real-world experience, not underpredict it.

I have owned a Ford Escape PHEV for more than a year. I have kept a complete log of my miles driven, gas purchases, and charging sessions including kWh measured at the wall outlet with a "Kill-a-Watt" brand meter. At the end of the first year, I calculated/estimated the performance of my car after 9,840 miles and found that I drove about 70% on plug-in electricity (2299 kWh used) and 30% in gas/hybrid mode (79.4 gal used). With plug-in electricity, I achieved about 101 MPGe (3.0 mi/kWh), which is just under the EPA rating of 105 MPGe for my Escape. In gas/hybrid mode, I achieved about 37 MPG, which is just under the EPA rating of 40 MPG. Note that I live in Tennessee with mild winters and my car is parked in a garage and doesn't have power-hungry accessories such as heated seats/wheel. I am sure my performance would have been worse if I lived further north with longer, colder winters.

Based upon my data and experience, I find it suspicious that you claim to be 36% more efficient in plug-in electric mode than the EPA rating for your car. While that type of performance may be possible for brief periods under optimum weather and driving conditions, I think it would be nearly impossible to sustain as a long-term average.

Justin Hart    April 5, 2023 - 6:01AM

In reply to by Fred (not verified)

It’s really pretty simple: I often get 37-43 miles of range out of my Sorento PHEV on a full charge. The only times I do not exceed the EPA range by 20-30%+ is in winter (when I have snow tires with higher rolling resistance on and the temps reduce battery efficiency), or when I have obstructive cargo on the roof (the cargo box) + a full load of people/stuff on board. All I have to do to handily exceed the EPA rated range is drive it gently and favor use of the battery for slower speeds (i.e. 50 mph or less typically). If I happen to be using the battery up for highway speeds only, I will typically only beat the EPA range by a few miles though, and so I rarely do that (it is very easy to keep it in EV mode most of the time on the freeways around Seattle though because our traffic is terrible, so driving 50 mph or less is kind of the norm). During each drive, I know when I have exceeded the 32 mile EPA range by looking at the fuel economy figures on the dash. If it reads “999” MPG after I drive 43 miles for example, that means I drove those 43 miles on electricity alone. If I switch between gas and electric, I just remember how many miles I had driven when I switched/switched back (that is admittedly tedious on a long drive, but I make a game out of it). I document all of this in a spreadsheet I religiously update. 3.2 was simply the average of all my monthly reported figures at the time (it is actually 3.16 right now, after the most recent months’ of data, which includes a few thousand miles of driving on snow tires in cold temps with heavy loads). The Sorento pHEV has 11.8 kWh of usable battery capacity (the rest is held in reserve for hybrid mode operation). With an average of 3.16 miles per kWh to date, that means I get a little over 37 miles of range per charge, cumulatively. Would you like me to do more reporting on specifics of the drives and conditions and my efficiency results? Any specific scenarios or details you would like me to measure?

Fred (not verified)    April 2, 2023 - 5:17PM

I have read many of your PHEV articles and agree with many of your conclusions. One question I have is how do you determine that your "lifetime miles per kWh figure is about 3.2" for your Sorento PHEV? 3.2 mi/kWh is equivalent to 108 MPGe, which is 36% higher than the EPA rating of 79 MPGe for your Sorento PHEV. I am an engineer by training and tend to be skeptical when there is a discrepancy this large. EPA ratings usually overpredict real-world experience, not underpredict it.

I have owned a Ford Escape PHEV for more than a year. I have kept a complete log of my miles driven, gas purchases, and charging sessions including kWh measured at the wall outlet with a "Kill-a-Watt" brand meter. At the end of the first year, I calculated/estimated the performance of my car after 9,840 miles and found that I drove about 70% on plug-in electricity (2299 kWh used) and 30% in gas/hybrid mode (79.4 gal used). With plug-in electricity, I achieved about 101 MPGe (3.0 mi/kWh), which is just under the EPA rating of 105 MPGe for my Escape. In gas/hybrid mode, I achieved about 37 MPG, which is just under the EPA rating of 40 MPG. Note that I live in Tennessee with mild winters and my car is parked in a garage and doesn't have power-hungry accessories such as heated seats/wheel. I am sure my performance would have been worse if I lived further north with longer, colder winters.

Based upon my data and experience, I find it suspicious that you claim to be 36% more efficient in plug-in electric mode than the EPA rating for your car. While that type of performance may be possible for brief periods under optimum weather and driving conditions, I think it would be nearly impossible to sustain as a long-term average.