Has anyone had this issue when pushing the gas it feels jerky… do you have to use the top tier fuel? This didn’t start until 900 miles(1000 now on van) it’s started at like 40 mph but now it’s almost anytime you accelerate . It’s not bad but it’s Noticeable ..
I have not experienced this exact symptom as you describe. However, we have noticed that when driving in SMART mode, which operates in ECO mode under light (easy) driving, we have experienced some light shuttering feel when at about 40-45. It's not what I would call very noticeable-- I'd liken it to driving on an irregular surface road. Anyhow, yes I have noticed this and sounds similar to what you're experiencing. Our 'Carni-van' has about 3500 miles and is a SX-P. I was considering mentioning it too on this forum. Also, I wondered if it actually has to do with ECO mode and is actually performing properly. I'm not sure if the vehicle has this feature, but it may be part of the fuel savings programming that may (in essence) shut off fuel to some engine cylinders during low power demand for economy. I think Honda may have had this feature on the Odyssey. It can produce a slight shuttering feel. Again, I'm not sure if this is how the KIA works. Also, we've used predominantly 92/93 gas, which may be overkill. There is some conflicting info about this. Our dealer's service manager told us that 87 was fine, but he said higher octane would provide better mpg and lower emission (I'm not worried about the emissions, frankly.) He also did not seem to be aware of the owner's manual suggesting higher octane gas vs. gas additives every 8K. It will be interesting to get feedback from other owners on this.