: Trying to diagnose weird issue driving issue at speed

10-17-12, 02:15 PM
I just picked up a 2011 coupe used with 9000 miles on it. The rear tires were shot so i had to replace them. I ended up getting ventus v12 cause theyre half the price and i personally dont think ps2 are worth the hype or money(not the point).
I'm coming from a lowered 07 V and i never doubted the handling at any speed. With the V2 it seems like at high speeds or randomly sometimes on the highway the car almost wants to veer as if there's a groove in the road causing it to pull one way or another. It feels like the front end wants to dance around a lil. This only happens when im decently heavy on the throttle it seems.
I was wondering if it could be the fact i have 2 different sets of tires or if i just need a road force alignment or if its something else. Thanks.

10-17-12, 04:59 PM
I just put on 4 new V12s on my sedan and though I have only seen about 95 MPH so far, I have not found any problems with stability up to that speed. In fact the new Hankook are more stable and quieter than the old PS2 I took off. Two different tires of varying age could be problematic. Also, did you get an alignment check when you replaced the tires?

larry arizona
10-17-12, 05:36 PM
for sure try road force! are you sure you are not just tracking on a rutted road surface? I never get darting like that unless the road is not very flat.

10-17-12, 05:54 PM
If you have one brand on the front and another brand on the rear, theres your problem.

10-17-12, 10:25 PM
Tires branding no way. That's a hype that manufacturers use to sell more tires. If the car is tracking right, it won't matter even if you go smaller or narrower. I'd go to an alignment shop and get a 4-wheel done and see what they say after it. Vibration etc is balance, wandering is alignment.

10-19-12, 06:08 PM
Thanks for the input. Yea well i am going to replace the ps2 as they're pretty old and almost at the bump stops anyway plus i'm OCD. Then i'm gonna go for an alignment later that day but im gonna give the 4 tires a run before that to see if i can make the symptoms reoccur. The only reason i feel it may be the tires is because of the major difference in age and the car wasn't driven much on them so they could've flat spotted(i do hear something akin to a rock stuck in the tread or a slapping from the front tire on the highway with the windows open).

10-21-12, 03:29 PM
Different tires will definitely cause some major issues. It may not be too noticeable on high profile economy/luxury car tires, but on low profile max performance tires, it definitely does. It's due to the differences in sidewall construction and stiffness, as well as issues with tread compound and pattern. Get new V12s on the front and your problems should disappear. In the meantime, be especially careful in the rain, as the difference in traction between front and rear could cause some serious instability.

Silver Sled
10-21-12, 07:02 PM
Check tire pressure front to rear.

10-22-12, 11:24 AM
I got new V12s put on and the problem is gone. Im gonna get an alignment just to make sure anyway but the car feels much more solid at speed now. The ps2s were pretty shot which definitely made it worse.