It's not so much the powertrains but the fact that there is a V6 and V8 model offered. Kia should have thrown down and said, "Screw it. We're going with a V8 model. We're not going to worry about the corporate average fuel economy (CAFE) standards in this case. We want to deliver a sedan that packs a powerful punch."
This is going to be Kia's first V8 engine (ed. note - in a sedan). The Korean automaker, in my opinion, should go all-in and say it's the V8 or nothing. The V8 sounds like it's going to be pretty spectacular. Tau DOHC all-aluminum 32-valve 5.0-liter engine produces 420 horsepower. Kia said at the K900's announcement, "The engine is designed for efficiency with gasoline direct injection (GDI) and dual CVVT variable valve timing on both the intake and exhaust. "
According to Kia, the 3.8-liter Lamba V6 produces 311 horsepower, making it the most powerful V6 in the lineup. A three-step Variable Intake System (VIS) is designed to provide optimum low- and mid-range torque. Similar to the V8, the Lamba V6 features GDI and CVVT technology to help improve efficiency.
It's safe to say that there is going to be very little performance difference between the two engines for the average driver. But, criminy, luxury doesn't come in a V6 engine. It comes from a V8, V10 or V12.
You won't see a V6 offered by Kia's sister company Hyundai for its comparable car the Hyundai Equus. There's a reason for that. The sister division knows what sells when it comes to luxury, which is why the Equus has managed to capture 9 percent of the luxury market in a relatively short time.
It's not that far of a leap to see it happening because the Hyundai As Warren Buffet, a famous Buick driver, might say, spending money for a nameplate like Mercedes-Benz or Audi when you can get the same value from a Hyundai or Kia is a huge waste of money.
Here are some other details on the V8, which demonstrate why it should be the only choice. A specially tuned air intake improves airflow while a roller-type timing chain and Teflon coated crank oil seal reduce frictional losses. The fast-heating catalytic converter helps reduce emissions and is of a lightweight design. The V8 is mated to a new smooth-shifting eight-speed transmission. Shift mapping is variable depending on the driver-selectable settings of Eco, Normal and Sport, and each mode also adjusts the electric steering’s sensitivity. (Granted, the V6 is also mated to the 8-speed, which means it has two gears that will probably never be used.)
Keith Griffin has been writing continuously about new cars since 2002. He used to be the guide to used cars at former About.com as well as a contributor to The Boston Globe and Automotive Traveler. He is the founder and president of The Internet Car and Truck of the Year, where "Internet Pros and Average Joes" pick the car and truck of the year. Currently, Keith is the managing editor for American Business Media. Follow Keith at @indepthauto on Twitter.