I just had my stock rear tires replaced (with the Kumho Ecsta SPTs at stock sizes) and still have the stock fronts. I just got them put on last week but had only been driving around town. Today I went on a 4 hour drive, primarily on highways. Anyway, at highway speeds, my car feels funny now... any slight steering input makes the whole car feel like its wobbling or something.... hard to explain, but almost feels like shimmying the steering on a wave runner/sea-doo. By the end of the drive I didnt notice it as much but maybe I was just getting used to it, idk??

Is this just a result of the tires not yet being broken in, or is there something else going on here??

Thanks as always!

Softer sidewalls than the Factory RE050a's.

this is a bummer.... i already dont like it, i feel like the car is less stable now

hopefully i will get used to it quickly

could be that since your front tires are worn down, they are 1-2 mm smaller than your rears so they feel a little funky?

just my guess

did you get an alignment?

i think its just the oil residue thats on the tires since there new. give it about 200 miles or so and it will feel normal agian.

and you wont need an alignment.

no... didnt get an alignment

HOPE it gets to feeling normal soon

is it possible that the SPTs just grab traction a little differently and are more responsive to steering input? I'm running the SPTs (much wider and lower profiles) and they definitely grab a little more and are much more sensitive to the steering input. I figured it was the width that was doing it but it could be a combo of the tires as well. I really like the tires but they do have a different feel than the stockers and it's probably the softer sidewall like Mike mentioned. Put a little more air in them and see if it helps.

i will try that!


will the softer sidewalls make the car any less safe..... say, when im taking my favorite circular on/off ramps at aggressive speeds? (aside from the fact that the tires are in fact new and need to be cautiously adjusted to)

not really any more unsafe than any other tire but I do feel that with too low of pressure, they'll have a tendency to roll and push just a bit during hard cornering...

i would figure that the thread of the front tires is trying to pull the car one direction and the rear thread is trying to pull the car another direction...making the car feel like it is unstable...happened to me one time when i had 2 different sets of tires on my 240....just my thought.

mixing tire types is more than likely your problem try to get a matching pair of the SPT's up front...its geneally a big no no for a daily driver to be mixing different tire types

best to replace all 4 tires at same time, or under/over steer could be the result, depending on which end you replace.