So I didn't think much of it, but for the last couple weeks or so the steering wheel has been shaking (most notably at speeds of 65mph or higher). It doesn't seem to affect the driving, but a friend of mine said it could be a warped or "tumor'd" tire and can lead to a blowout. I only notice the shaking on the highway when cruising/accelerating, not when I brake.

 

Check the balance first. I have found that the low profile tires for this car are hard to keep balanced.

 

Also could be alignment.

 

I'm going to have it checked out during the weekend, but in any case is it still safe to drive? I commute about an hour each way via highway to school

 

Mine has been shaking like that for about 6mo now. I figure its the tires so I'm gonna wait till theyre shot before I replace them.

 

Having the same problem. I had the car for only 2 weeks, so I went to the dealers to have the wheels balanced... the wheel still seems to be shaking. I am beginning to think that its just me being paranoid since when others are in the car they claim to not feel shaking of any kind. Anyone else in this boat?

 

so I finally went to big o tires and they informed me right off the bat that it was a tire balance problem. A quick $10/ tire and the shaking has stopped so far. I was told that tire balancing should be performed every ~10k miles but I'm unsure if the mazda3 is more susceptible to tire inbalancing compared to other vehicles.

 

My Mazda3 has ~31,000 miles on the clock on the original balance. No vibrations so far.

 

The other thing to be ware of is that alot of small town/low key tire shops fail to do the weights in the center of the wheel, they only mess with the ones on the outer lip

 

center weights? stickies and ones that clip on the outer lip are the only ones i know of