Overachiever - Nearly 600 Miles and 40 MPG on One Tank - 2016 Kia Optima Long-Term Road Test

Edmunds.com

Overachiever - Nearly 600 Miles and 40 MPG on One Tank - 2016 Kia Optima Long-Term Road Test

We drove a 2016 Kia Optima almost 600 miles on one tank of gas and got 40 mpg.

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5vzfe

I don't want to rain on your parade, but is it really overachieving if the car is meeting it's stated MPG rating? You could create an argument for the Ram and the Volt (electric range) qualifying as overachievers, perhaps.
Don't get me wrong, those are impressive numbers, especially considering the driving circumstances, and the size of the car relative to it's engine. I guess maybe those reasons are enough to be overachieving by themselves, but still, the numbers you posted match what the EPA says you should.

don_quixote

I guess you saved it for the next post, but how was the drive? Did you have a moment that this little engine was struggling?

subytrojan

Kudos for posting the actual calculated average instead of just the indicated one, Brent!

allthingshonda

Proves that if you keep the turbo boost down small turbocharged engines are fuel sippers.

longtimelurker

Excellent. Very small displacement, a long overdrive, light weight, good aerodynamics and steady speed = keeping it out of boost. And I am thinking they may be doing some exhaust manifold cooling with this thing, too.

vvk

The latest crop of large family sedans has been nothing short of spectacular in offering superb comfort, plenty of passenger room, great safety ratings and terrific fuel economy. My 2012 Passat achieved similar fuel economy and range with its five cylinder engine and very long fifth gear. I was getting around 38 mpg on long trips, slightly less in winter.

daryleason

I know that I don't always agree with what Edmunds posts, but lately, I've had a niggling little feeling in the back of my head as I've read them. What's going on, Edmunds? In the past, your posts were more...impulsive, intuitive, real-world. Now, we get a lot of posts about MPG, whether a bike will fit, but not so much about the driving impressions, especially in daily use, that y'all used to provide. They're more clinical, like "I can measure this amount of information in a controlled environment" instead of "this is how the car is making me feel about it today." Maybe it's the cars, but lately, the reviews just don't seem to convey a passion for driving. If it's the cars, get better ones. If it's not the cars, then y'all need to reconnect with what your company was doing before, because y'all are drifting out of your lane worse than a car with a bad steering linkage. No offense, Brent Roman, because I'm not trying to single you out. This is more as a whole.

agentorange

Are we all on the same page as to what "keeping it out of boost" really means? Years ago a study by Saab showed that steady speed running with some positive boost was better for gas mileage as the inlet pumping losses were reduced to almost zero. I would guess that if the manifold pressure were monitored on most modern turbo cars in the steady state they would show no vacuum and maybe a little positive pressure. As for turbos sucking gas around town, that's because of the enrichment required to save the engine from the digital right foot driver.

longtimelurker

agentorange said:

Are we all on the same page as to what "keeping it out of boost" really means? Years ago a study by Saab showed that steady speed running with some positive boost was better for gas mileage as the inlet pumping losses were reduced to almost zero. I would guess that if the manifold pressure were monitored on most modern turbo cars in the steady state they would show no vacuum and maybe a little positive pressure. As for turbos sucking gas around town, that's because of the enrichment required to save the engine from the digital right foot driver.

I think you are right about the slight positive pressure. The sucking gas around town is helped by cooling the exhaust manifold so that enrichment is not needed to cool the cat.

allthingshonda

At only 1.6 liters even a constant highway cruise requires the turbo to provide some constant boost. What I mean by staying out of boost is the around town full boost acceleration. Mild acceleration and a steady cruise in a small turbo engine will allow it to sip fuel like a NA 1.6 4 cylinder engine. Dip more into the throttle and the turbo will perform like a bigger more powerful engine but will also drink gas like a bigger engine.

thecardoc3

Pumping losses are reduced today by variable cam timing, variable valve lift (when used), and electronic throttle controls. GDI has the ability to run stratified air fuel charges, which result in a very small combustion event which is surrounded by exhaust gasses that remain in the cylinder due to increased overlap under some operating conditions.

With GDI, even the most basic systems are so different from port fuel injection, you need to study them like you have never worked on anything before. It takes a lot of time to understand how GDI often operates at air/fuel ratio's that are not at lambda by design.