Petrol versus diesel; what is the best choice when it comes to Kia's big family SUV?
Where does the modern family turn to for a safe, comfortable and value-packed hauler these days? I think they are spoilt for choice.
There’s a record number of manufacturers competing in the SUV space, and it’s hard to find a dud amongst them.
The 2019 Kia Sorento is one large SUV definitely worth looking at, being a strong performer in recent CarAdvice testing and comparisons. Unlike some, you have an option of drivelines across the range.
GT-Line is the most expensive and spec-laden option for the Sorento range, with a price of $55,490 and $58,990, depending on which driveline you go for.
The cheaper GT-Line is petrol powered: a 3.5-litre V6 that develops 206kW at 6300rpm and 336Nm at 5000rpm, using E10 unleaded petrol and powering the front wheels.
Spend an additional $2500, and the motor is a 2.2-litre turbo diesel that makes 147kW at 3800rpm and 441Nm at 1750–2750rpm.
Both options run through an eight-speed automatic gearbox, but the diesel-powered Sorento also gets an on-demand all-wheel-drive system.
Going for GT-Line specification does net you some nice creature comforts: heated and ventilated front seats; even the second-row outboard seats are heated.
Interior and features
The user-friendly design of the interior is clear, with the right controls and buttons being easy to find. The dashboard itself feels like it’s made of the same soft-fall material they use in kids' playgrounds – not a scratchy hard plastic, and should be hard-wearing.
The infotainment unit is the bigger 8.0-inch display, but runs the same operating system as other Kia (and Hyundai) product. It has all of your favourite digital doodads: Android Auto, Apple CarPlay, native navigation and digital radio.
While the layout is good and practical, you could say the interior is a bit boring. It’s an all-out black affair, and feels lacking in character, especially when compared to the Mazda CX-9 and Hyundai Santa Fe.
Special mention must go to the panoramic sunroof, which is generously sized. With the blind rolled away, it goes a long way to helping this otherwise very dark cabin feel spacious and airy.
Other niceties of note for the GT-Line: 10-speaker sound system, integrated sun shades in the second-row doors, smart key, push-button start and 360-degree camera system.
That camera is a ripper, by the way. It has a few different viewing modes, and makes lining up the reverse parallels a piece of cake.
When you’re all dialled in comfortably behind the wheel, there’s good space left over behind for passengers. The second row has a 40/20/40 split, and can slide fore and aft for extra adjustability.
With that in mind, those in the second row (if they are so inclined) are able to free up some additional room for those in the third row.
With a bit of additional leg room freed up, space in the third row is reasonable. Your knees aren’t hard up against the seat backs, but they are high nonetheless.
The sunroof does steal a bit of head room from you, as well. Only the least-complainant adults amongst us would likely put up with it for any long distances.
What is good in the third row are the features. Those in there might forget the discomfort as they adjust the air-conditioning control, and have somewhere to stick their water bottle. And while I’m on the subject, air vents, USB power and a 12V plug are handy additions in the second row.
Niceties aside, the Sorento is a good performer in the storage stakes. There’s a couple of lidded cubbies around the gear shifter, and the centre console is a good size.
There’s room for a decent-sized bottle in the door cards, along with a handful of other stuff that always tends to collect in these places after a couple of weeks. You might be flat out keeping the smudge marks off some of those shiny black finishes, however.
With all three rows up, there’s 172L of storage space at the back. It’s decent, and I like the fact that the cargo blind is stored away in its own spot. There’s a full-size spare there as well, which is underslung.
Fold down that third row, and room grows to 605L. Don’t forget the sliding 40/20/40 split second row, which can help free up some additional space when needed. Set up only as a two-seater, and you’ve got a mammoth 1662L at your disposal.
Ride and comfort setup
Kia is well known for its local suspension tuning and development work here in Australia, and the Sorento is another proud graduate of the programme. The Kia has a very non-complainant nature about it when driving around town.
There are no flash active components to the MacPherson strut (front) and multi-link (rear) geometry. While it’s not out-and-out luxurious, it’s certainly compliant, responsive and controlled.
Steering, with electric assistance, is an equally painless affair. The turning circle (11.4m) is good for a vehicle of this size, and you aren’t left feeling worried about tight manoeuvres. It’s not a sporty car to drive through the corners, but it has enough response and feedback to not feel vague.
Down to it: Petrol v diesel power
If you’re looking at the Sorento range, one big decision you’ll be looking to make will be between the two options of drivetrain: petrol or diesel.
Often, this is a decision guided by personal preference and circumstances, rather than choosing which one is flat-out better. But in saying that, I might be able to help those who are stuck somewhere in between.
The petrol engine makes 59 more kilowatts at a higher point on the tacho (6300rpm v 3800rpm).
Peak torque is where the diesel is stronger: 441Nm at 1750–2750rpm versus 336Nm at 5000rpm. More torque, much lower down, and across a range of revs.
Gearbox tuning seems to be well sorted between both the diesel and petrol options, shifting at the right times and not too often.
The diesel surges forward on that wave of torque, while the revs really pick up on the petrol motor to start moving, revving in that typical naturally aspirated V6 eagerness.
Neither is slouchy, but the V6 is certainly the faster of the two. It’s a bit quieter, as well. The diesel engine isn’t too noisy: the diesel engine clatter is well muffled, but it’s still there regardless.
One big difference, naturally, is the fuel consumption. Listed combined consumption for the petrol Sorento is 10.0L/100km versus 7.2L/100km on the diesel.
There isn’t much difference in highway cruising, 6.1L/100km plays 7.6L/100km. But the big difference is extra urban (stop-start town) driving: 14.2L/100km v 9.2L/100km – five whole litres per hundred difference.
In our testing, our results mimicked these numbers pretty closely. The diesel was reading in the mid 8.7 litres per hundred, while the petrol averaged 12.2L/100km on a similar (but not identical) run.
It’s worth noting here, we did get 8.5L/100km out of the petrol after a 100-ish kilometre highway run. It can be economical, but it depends on what kind of driving you are doing.
The other big difference between the two is the drive type: while the V6 petrol gets away with only a front-wheel-drive set-up, the diesel engine scores AWD. And you can’t have one without the other.
Having extra driven wheels can be of a big benefit, but only when you’re driving in situations and conditions that might outstrip what the front end can offer.
The AWD system is an ‘on-demand’ one: normal toddling around town in the AWD is effectively like a FWD, only the front is being driven.
If the car senses slip or wheel spin, it progressively closes clutch packs in the rear differential to start shuffling drive towards the rear, giving you a bit of AWD ability. This is handy on wet bitumen, slippery dirt or anything steep or slippery.
If you’re sniffing around some tricky, uneven surfaces or a bit of light off-roading, there is an AWD lock button to help tighten things up further. From the driver’s seat, it doesn’t feel like it locks things up completely. But it’s certainly better than the FWD in that environment.
Servicing costs are a close run between the two, with both benefiting from seven years' worth of capped-price servicing. Over that time, or if you rack up 105,000km first, you’ll be dishing out $3479 for the diesel or $3081 for the petrol – $398 worth of difference.
When you consider there’s a turbocharger, intercooler, particulate filter and AWD system to take care of, the difference isn’t what I would consider big.
Another small difference between the two is kerb mass, with the diesel being 110kg heavier (1985kg v 1875kg tare mass).
Its GVM is only 30kg higher, however, so you have a little bit less payload in the diesel Sorento. Both have the same braked towing capacity of 2000kg, with a limited towball capacity of 100kg.
The end decision does draw the adage about horses and courses out of me, regardless of how clichéd some might find it.
The AWD and diesel combination does improve the Sorento’s appeal for those who live in slippery or mountainous areas, or take on some inclement conditions and dodgy roads often.
And while you are able to consume much less fuel in stop-start traffic, it’s very difficult to recommend a diesel for somebody who is going to be doing lots of short runs and sitting in traffic all day. Diesel particulate filters, turbochargers and intercoolers don’t fare well on short, cold trips.
When you include the extra costs involved with purchase and servicing, it’s hard to go past recommending the V6 petrol for 90 per cent of punters. You’ll cop an efficiency penalty around town, but there is more to the equation than just fuel consumption.