2015 Kia K900: Better Tire Pressures
May 22, 2015
I've been playing with the tire pressures on our long-term 2015 Kia K900 and I think I found a sweet spot.
Believe it or not, factory spec is a comically low 31 psi (cold) in all four Hankooks. It feels like it. Every time I drive the car I think it feels like the tires are low. So I check, only to find out they're exactly at the factory spec of 31 psi. After 10 months and nearly 15,000 miles, I decided to do something about it. I decided to try some higher pressures to see if the car felt better to me.
First I pumped them all up to 33 psi cold. The car immediately felt better. It had more directional stability and more response with little to no ride degradation. After a few days I went further, pumping them all up to 35 psi cold.
Wrong move. The Kia immediately felt like it had concrete for rolling stock. The ride was crashy and the steering picked up an uncomfortable amount of kickback. Suddenly the car felt crude.
But the problems seemed limited to the front suspension. Things felt good out back. The K900's rear suspension liked the higher pressure. Stability improved and I began to feel a modicum of athleticism in the chassis. So I mixed and matched.
After 100 miles, I went back to the tire gauge and bled the front tires back down to 33 psi cold, but left the rears at 35. Done. The car feels 500 percent better. It still has its luxurious intentions, but it now responds to inputs without the sloshy, disconnected feel it has at the factory spec.
We'll keep an eye on fuel economy and report back.
Scott Oldham, Editor in Chief @ 14,952 miles