Definitely sounds like you've got (2) different things going on.....Any local gas station should also have dry gas (If that's more convenient) Sometimes it's called fuel antifreeze.

I wonder if you increase the air pressure you keep in the tires if that would help some on the flat spots (tire would have more resistance to flatten into ground)

 

Well, what tire pressure are you at. The tires may take longer to gain air pressure. Because as the heat increases in a tire, tire PSI also increases. The tires may just be low on pressure.

 

The brand of tire is the Avon Tech Mech 500 A/S...

You need to be carefull because they are rated very high! But if you dig through it all I found all of the negative.

I have the tire pressure at 31 psi. Maybe Ill put them up higher to like 35.


But as long as I know what is going on now. Should I replace the tires? Or will the vibration not hurt the car?

Another thing that is scaring me is the same problem that M6Newb is having. The vibrating when the car is idle.

 

well Mazda says the low profile tires should be at 32 psi.

 

I agree to that...But I was thinking if they were a little bit harder there would be less flat spots...Do you think the vibrations will hurt anything on the car?

 

Just for kicks, rotate your tires to see if it changes anything.

If the vibrations are severe, I wouldn't leave it that way. If you are feeling them, so is your car. You'd probably wear out your struts and tie-rods faster if left alone.

The vibrating at idle could definitely be some water in your fuel. How many total miles are on your car? Have you ever changed your fuel filter?

 

Its not to bad, just for the first few minutes. My car has about 39,300 miles. I have never changed the fuel filter. Ill have to have them check on that...When I bring my car in on friday Ill have them rotate the tires. Thanks again.

 

Some performance tires still use nylon belting in the sidewall. You said it's been cold lately...most likely answer to your question is that the tires are developing temporary flat spots from sitting in the cold overnight. Once the tires warm back up from your first few minutes of driving they return to their normally round shape..

 

http://www.finishlineperformance.com.../docs/0036.pdf
motor mount maybe? I know, this is for vibration at speed, but it may be part of your issue.

 

I may be totally off base.. but im used to driving a jeep that had a lot of tire issues on the highway. When it gets cold outside.. your tire preasure drops... and sometimes can leave 1 tire lower then the other. Even with new tires, depending on how hot or cold it is.. it can effect each tire diffrently. Quick fix: Buy a tire pressure gauge. ( 3.00$ at gas station ), and check your tires manually. Even if the tires are only off a few pounds.. combined with the cold.. it may turn that into a slight wobble. Also check ityou are using 2 diffrent style tires ( ie 2 racing, 2 all season ) again.. the traction on the tire could play a small part.

Lastly.... very uncommon but it DOES happen... check to make sure your tire was put on properly. If there was a kid or someone in a hurry to put on your tires back on,he may have tightened the nuts wrong. ( not crosstightening, butrather clockwise tightening )This allows for the bottom nut not to get 100% snugwhen lowered whichleaves your car on a slight angle. This will lead to a click sound when you take a specific 90degree turn OR to a wobble when you drive. Again... i know this due to changeing a flat this winter. I had placed the tire on wrong due to not lifting the jeep high enough off the gound. Once i removed the tire and repeated the process with a good jack.. my tire wobble was gone.

Hope this helps.. if not.. at least i tried : )