Kia Optima vs Lexus GS350

What's the difference?

If you travel long distances, want a good amount of space and don’t want to pay big bucks for a new car, then yeah, maybe there is a reason sedans like this will hang around for a while longer.

Sure, the appeal of sedans mightn’t be as strong as it once was, but models like the Kia Optima prove they still have a reason to exist.

Weirdly, given all the good things I've had to say about the GS F Sport, it doesn't quite hang together. It's missing that certain something the Europeans have in their chassis, particularly the BMW 5 Series, and with ageing interior tech, it's struggling to keep up.

It's a car built for specific tastes, and they're more California than Straya. And that's perfectly okay, but unfortunately, that doesn't translate to a stampede of buyers. Having said that, none of its German rivals (or its beleaguered Japanese counterpart, Infiniti) could claim wild sales success either.

The GS is a terrific car, underrated but also just not quite there for my taste. The GS F, though, that's another thing altogether.

Cosmetic changes for the facelifted 2018 Kia Optima include new headlights and tail-lights with revised LED signatures (but still halogen lamps in the base model), and there are newly sculpted bumpers and new wheel designs across the two-model range. 

We had the base model Si, which doesn’t look as good as the GT model, because it has smaller wheels, the sporty body kit and misses out on the LED headlights, but the LED daytime running lights are still present.

The GT has a more aggressive look, and the side skirts, front spoiler and rear diffuser fit it better - there are dual exhausts, but not sporty quad exhaust tips.

In fact, this model is a bit like the old-man version of the Optima. No offence intended to old men, of course. The GT is just heaps sportier, and I reckon it’s considerably more attractive as a result. 

Still, the inherent sleek styling of the Optima remains - the chrome highlighting along the window line is a bit too sheeny for me, but the angles and stance of this model are quite gracious. I really dig the fact the top of the windscreen mirrors the ‘Tiger Nose’ grille shape.

I'm no exterior designer, but I liked the existing Optima more - it just looked a bit neater, even though it had a decent amount of bling with its Mercedes-like diamond-pattern grille, as opposed to the cheese grater look seen here.

There’s not quite as much bling inside the cabin of the Si, either, but it is still a well-designed space - just not as special as the premium package offering of the GT (which gets leather trim - not nappa leather, but still a quality cowhide finish, and more). Check out our interior photos to see if you agree - but size and interior dimensions of the Optima are hard to argue against.

The GS is ageing well, but it's still a bit heavy-handed around the headlights and a little on the slabby side along the flanks. It doesn't look poised for action, even with the F Sport additions, but nor does it look frumpy, mostly due to the whopping blacked-out spindle grille, a Lexus signature. 

The rear end is good looking but a bit bluff, again neither surprising or delighting.

Little has changed inside, but it's still a very nice cabin, and always will be apart from a couple of clangers (the gear shifter looks super-cheap). 

What's more, it's welcoming, lots of very nice materials, comfortable, seats - it's exactly what it needs to be. Whatever you might think of the looks, one thing is absolutely certain - if anyone builds cars better than Lexus, it's a very, very short list.

I really like the way Kia designs its cabins. Sure, there’s a lot of black in here, but there’s also a lot of thought put into the usability of the space.  

The high-mounted 7.0-inch infotainment and multimedia touch screen in the Si is simple to use, and for 2018 the Optima range gets Apple CarPlay and Android Auto - you couldn’t get that in the Optima up to this point. 

Also included are a reversing camera, USB input, Bluetooth phone and audio streaming and six speakers. The Si model misses out on sat nav - you’ll have to use the maps app on your phone. No DVD player either.

Storage is well thought out in here, with big bottle holders in the doors, a good sized pair of cup holders up front, and a nice little storage bin for your phone, wallet, keys and so on.

There’s a driver info screen with a digital speedo, and even on this base model you get a dual-zone climate control air conditioner. The updated Optima gets a new steering wheel, too.

Now, what about the back seat?

It may be considered a ‘mid-sized’ sedan, but there’s limo-like space. With the driver’s seat in my position (I’m about six feet tall) there was still heaps of rear legroom in the rear seat, with ample knee room, good foot room and decent shoulder space, too - three of me could slot across the back bench comfortably, which means kids will fit easily, too. There are three top-tether points and two ISOFIX points as well.

Kids and adults alike will be happy with the rear air vents back here, and there’s a flip down armrest with cupholders, too. Again, big bottle holders appear in the doors, and there are map pockets in the back seats.

What about boot space? With so many people choosing SUVs over sedans because they’re theoretically more practical, the Optima offers good food for thought - it has enough luggage capacity for a bunch of suitcases (510 litres VDA in size) and there’s a full-size alloy spare under the boot floor. If you need more, you could always invest in a roof rack setup?

Being a big car, there's plenty of room inside. Four passengers will be very comfortable although rear legroom was a bit on the skinny side given the car's size.

The cabin contains a good-sized console bin, four cupholders and each door pocket into which you could conceivably slot a bottle.

The 520-litre boot is a useful shape, with a sensible load height and a space-saver spare under the floor. The 5 Series and E Class both best the Lexus by 10 litres, so the GS isn't far off the norm.

We had the pleasure of the GS 350 F Sport for the week, which is well over $10,000 cheaper than the Luxury and is therefore the 'default. If you're not sure what F Sport means, it's Lexus' answer to an M Sport or AMG pack, without all the high-powered engine shenanigans to go with it. If that's what you're after, the V8-powered Lexus GS F is definitely for you.

Starting at $95,300, the F Sport has a spectacular standard features list - 17-speaker stereo, 19-inch alloys, variable-geared four-wheel steer (!), adaptive suspension, dual-zone climate control (with moisturising function), hectares of leather trim, head-up display, electrically-operated heated and ventilated front seats, rear sunshade, F Sport instrument screen, auto LED headlights, keyless entry and start, sat nav, front and rear parking sensors with around-view cameras and a space-saver spare.

The media system is run from Lexus' 12.3-inch screen embedded in the dashboard and controlled from an infuriating console-mounted mouse-clicker with a couple of shortcut buttons. It really is spectacularly irritating and made worse by the rotary dial stationed next to it that acts as the drive mode selector. Why not use that instead? 

As ever, the system is mildly baffling to use and hard to look at, but the sound is absolutely lovely from the Mark Levinson-branded speakers. Lexus is persisting with a DVD player but it also has DAB+.

The Si model is powered by a 2.4-litre four-cylinder petrol engine, which has seen no changes to its specifications for this mid-life update.

Engine specs remain at 138kW of power at 6000rpm, while torque is rated at 241Nm at 4000rpm. It makes use of a six-speed automatic transmission only - there’s no manual transmission here, but you do get paddle shifters - and it's front wheel drive (the Optima isn't available with AWD, or as a 4x4, or in rear wheel drive - the latter is left to its bigger brother, the Stinger).

The GT gets a zestier drivetrain with more horsepower - it has a 2.0-litre turbo four-cylinder engine with 180kW/350Nm, which is much more desirable, but also louder than the Si’s 2.4. It also has a six-speed auto transmission, and is FWD. If you're into ratings and statistics, that 2.0-litre with a turbocharger is one of the perkier offerings for its engine size in the class.

There is no hybrid model available, despite a plug in hybrid petrol version (allowing you to run in EV mode) being sold in European markets. No diesel here, either, while other markets get a 1.7-litre turbo diesel. No LPG model here, or anywhere else, for that matter.

Towing capacity for Optima models is 750kg unbraked and 1700kg braked for the 2.4-litre, and 700kg/1400kg for the 2.0-litre turbo. Tow bar down-weight is capped at 80kg.

If you're concerned about engine problems, suspension problems, clutch and transmission issues, be sure to check out our Kia Optima problems page.

Lexus fits a 3.5-litre (2GR-FKS) naturally-aspirated V6, delivering 232kW/380Nm to help shift the 1745kg GS. Power goes to the rear wheels via an eight-speed automatic. Lexus claims the sprint from 0-100km/h is completed in just six seconds.

Kia claims a very realistic fuel economy rating of 8.3 litres per 100 kilometres for the Si model, and we saw damn close to that consumption during our week of testing. On the highway it will sit at around 6.5L/100km, ensuring good mileage, while city driving will push usage above 12.0L/100km. Our overall average was 8.5L/100km, which is good. Use the eco mode, and you'll get a little better use.

The turbocharged GT model uses a little more, according to Kia’s 8.5L/100km combined average claim, but we guarantee you’ll actually use more than that because it’s more eager to please.

Fuel tank capacity is 70 litres - plenty of size for long distance drives.

A real world 13.7L/100km is a solid miss of the claimed 9.3L/100km, which itself is hardly earth-shattering. It's a big heavy car and that's the penalty. It drinks fuel fast, so the 66-litre fuel tank does drain quickly and it's worth knowing you have to fill it with the 95 RON or better.

The Optima has some really good elements to the way it drives, but sadly  some less impressive bits as well.

Let’s start with the not-so-great stuff - the 2.4-litre engine in this Si model just isn’t as enjoyable as the turbo unit, and the fact that Kia still doesn’t offer a hybrid version here, despite doing so elsewhere, is a bit of a downer.

The drivetrain isn’t terrible - the six-speed auto is smart enough, and there’s usable power if you boot it. The two more sedate drive modes, 'Eco' and 'Comfort', mean the transmission will aim to save fuel and limit throttle response, with a bit more of a lazy feel to the drive experience. But in 'Sport' mode it is definitely more rewarding in terms of acceleration and performance, offering a bit more pep and urgency (we didn't do a 0-100 km/h speed test, but take our word for it); it undoubtedly at the cost of fuel consumption.

It’s just a bit of a shame Kia doesn’t offer the turbo in this spec, too. Fuel use for the Si model is better than the turbo, however, so it could be ideal for buyers who are more worried about the bottom line than design and a sportier drive.

The thing I like most about the Optima is its road manners - the steering and suspension have been tuned for local conditions, just like all Kia products, and it shows. 

The electric power steering is really well sorted, making for easy parking moves and good assuredness at higher speeds. And the turning circle is decent, too - 10.9m (so, the turning radius is 5.45m). 

Plus the ride comfort is really good. On the highway it coasts along with very little fuss, and around town it deals with lumps and bumps impressively. Sharp edges can upset things a tad, and mid-corner bumps can make it jitterbug a little bit, but not to a degree that would rule it out of contention if you want a mid-sized sedan.

It’s pretty quiet on the open road, too, and the adaptive cruise control makes long-distance driving a simple task. The GT does suffer a little bit more road noise, though.

There are things you expect in a Lexus. Quietness. Composure. Smoothness. The GS delivers all three of those things effortlessly. But it has a few extra things in its bag that I can't say I was expecting.

For a start, the 3.5-litre V6 moves the car without any carry-on and in doing so, I was constantly amazed at how quickly the speed in the head-up display reached the posted limit. It just doesn't feel or sound like a six second car, but there you are. The transmission is virtually faultless, the engine sound distant and refined, the power impressive.

It's a heavy car, no question, but two things work to make it feel much lighter. First - and it doesn't matter which mode you choose - the adaptive suspension somehow knocks about 200kg out of how heavy the car feels. The brakes, while a little soft on pedal feel when you first step on them, are very effective and again help to make the car feel lighter than it is.

The four driving modes are quite distinct. As usual, Eco makes everything soft and doughy or as I prefer to say, unpleasant. Normal is great for every day, with just the right throttle response and steering weight.

Moving to sport ups the aggro slightly while Sport+, while never harsh, firms everything up to the point where it starts to feel like a different car. Sport+ makes the car feel race-car pointy, the suspension holds the body in check and the power seems readily available without jerky progression

The all-wheel steer is a big part of the change in feel. It's is especially sharp in Sport+ mode. The steering's gearing changes up quite a bit, meaning a lot less steering lock required for your favourite hairpin bend. Of course, at real speed it all calms down because neither you nor Lexus are fond of sneezy lane-changes or Armco-swiping. At first I thought it just made the big car feel a bit too nervous but as I got used to it (and was able to dial it down by switching back into a less racy mode) I found it fun but a little bit out of character with the car itself.

And just because it's the F Sport, that doesn't mean it can't do all the things you'd expect from a Lexus. You can still waft, you can still creep up on people and it's really very comfortable when you're cruising or stuck in traffic. 

The GS scores 10 airbags, ABS, stability and traction controls, blind spot monitoring, rear cross traffic alert, forward AEB, active cruise, auto high beams and lane departure warning with lane keep assist.

The GS doesn't have an ANCAP or Euro NCAP rating while the USA's IIHS (Insurance Institute for Highway Safety) rating is good for each key crash-worthiness measure. The IIHS suite of tests is quite rigorous but differ from our ANCAP/Euro NCAP standards.

Kia remains a shining light in terms of its new-car-ownership promise, with a very strong seven-year/unlimited kilometre warranty. It makes a lot of sense if you plan to hang onto the car for a while. There's no extended warranty available, which is understandable.

That plan also includes a roadside-assist plan for the same seven-year period, provided you maintain your car with Kia Australia. So, given you get one year to start with, then you get an extra year of cover every time you go back to Kia to get your car serviced, you could end up with eight years of coverage. Nice!

Servicing is due every 12 months or 15,000km, with the first seven years covered by a capped-price-service cost / maintenance cost plan. The costs are: service one - $289; two - $466; three - $360; four - $559; five - $325; six - $599; seven - $345. That makes a total cost of $2943, which is competitive for its class. Keep your owners manual or logbook up to date, and your resale value should hold up better.

If you have concerns about common problems, issues, reliability ratings and durability, you should check out our Kia Optima problems page.

There's one area where Lexus smashes the Germans and that's after-sales. While the warranty is hardly ground-breaking at four years/100,000km and service intervals are reasonable at 12 months/15,000km, it's how it all comes together.

For the duration of the warranty, when the car needs a service, Lexus will either come and get it then return it to you, or give you a loan car. Anecdotal evidence suggests this continues long after the warranty runs out. Like, 10 years after the warranty runs out. 

This is a small thing, but if there's one thing I hate about car ownership, it's the servicing experience. If I was a betting man, I'd dare you to find someone who genuinely has a problem with Lexus after-sales care.

On top of that, you get a generous roadside assist package for four years.