The Kia Rio is fun to drive, with a willing engine, 6-speed transmissions, and capable if unsophisticated suspension. It conveys willing, youthful energy.
A 1.6-liter four-cylinder engine is the only one offered. It employs direct fuel injection, first used on a street car more than 50 years ago and still reserved primarily for more expensive cars. This yields good power and fuel economy. The Rio's 138 horsepower is better than anything in the class except the Chevrolet Sonic with the same rating. Peak torque is 123 pound-feet at a fairly high 4850 rpm, but again this has most of the class covered, except for the Sonic's optional turbocharged 1.4-liter at 148 pound-feet.
The Rio needs to be revved for maximum power, but so do most gasoline engines. This one is smooth so it doesn't really matter if you want to push hard because it adds only a bit of busy noise, absent the vibration or harshness. And with the most power and among the lightest weight in the segment, the Rio accelerates comparably well.
Fuel economy is another good story for the Rio. EPA numbers are 30/40 mpg City/Highway, which are unmatched by the Fiat 500, Honda Fit, Toyota Yaris, Ford Fiesta, Nissan Versa, or Chevrolet Sonic, though a couple of them can match the Rio automatic's EPA Combined rating of 33 mpg. Even the special fuel-economy models that account for a small fraction of sales don't rate 30 mpg City with an automatic. (Keep in mind these are EPA estimates and driving style makes far greater differences.)
While Rio's direct injection helps fuel economy, so do 6-speed transmissions where competitors often use 4- or 5-speeds. More gears allows better acceleration, lower highway engine speed, or both, hence better performance and fuel economy in the same car.
An optional Eco Package on the Rio EX features an automatic stop/start feature, dubbed Idle Stop and Go (ISG). Often found only on more expensive cars, this system switches the engine off at stops and restarts it when time to go, saving gas in urban situations and adding one mile per gallon to the city rating. ISG requires nothing of the driver: No switches to activate, no shifting into neutral, no special pedal techniques. As the car stops with the brake pedal depressed the car disengages transmission from engine and switches it off. As you lift your foot off the brake pedal the car restarts and you drive off as normal.
The automatic stop/start system on the Eco package works just as it should, and helps save fuel if your daily commute involves lots of stop-and-go traffic. On a hot, humid day with AC on, we averaged near 35 mpg, not bad in light of the circumstances.
Both transmissions are easy to operate. The automatic has been programmed for economy so you have to be forceful with the gas pedal to effect a downshift when speed is needed, or you can shift manually; it will hold the gear selected even if you mat the accelerator in sixth gear. The manual offers light throws and clutch action, not as precise as a Fit perhaps but we never got the wrong gear. Throttle activation has been tamed relative most recent Kia models, so it doesn't jump forward with just a minor touch on the pedal. Rio now has hill start assist to keep it from rolling backward on uphill starts.
On the road, the Rio feels quite comfortable, though the road surface determines how much noise seeps in from the rear tires. The ride is taut without being firm, the feeling one of stability and not punishment. Wind noise is not an issue, at least up to Interstate speeds, and the 6-speeds allow relatively low engine speeds for most highways so there's no mechanical noise.
Economy cars aren't designed for top handling marks but frequently make plausibly entertaining drives because they weigh less. With just 2500 pounds to control, the Rio has low mass on its side; it changes direction with minimal effort and no drama. The electric-assist steering is vague on center (many are) but does offer up some feel at speed.
The Rio SX, top of the line in luxury and sportiness, adds bigger front brakes, slightly firmer suspension settings and 17-inch wheels for a minor improvement in responsiveness at a minor cost in ride quality. We imagine the majority of SX buyers go there for the features but some will find the ride/handling balance skewed more to their liking and pay the features-heavy price premium to get it.