What can cause a steering wheel to shake and vibrate?
As others have said, it’s usually down to wheel alignment or balance and is usually noticeable after a tyre change if the change wasn’t properly handled. Occasionally this can also be caused by one of the weights placed on the wheel by the garage to balance it suddenly detaching (though this is rare).However, if you notice any sudden change, I’d certainly advise you to stop IMMEDIATELY and check what’s wrong.One day, a few days after a tyre change, my steering started to noticeably start wobbling badly as I was overtaking someone at 70Mph on the motorway. Due to the suddenness and violence of the wobble, I assumed one of the lead balances had suddenly come off and I decided to pull in immediately to the hard shoulder but as I was pulling in below 40 Mph, there was an almighty bang and shudder in the car and I found myself watching the left wheel of the car running away into the distance - luckily off the motorway, into a field.I managed to steer onto the hard shoulder with the car running on 3 wheels and the brake disk of the missing wheel - it turns out that the garage hadn’t tightened the nuts well enough and they came loose and out mid drive.Motorway recovery eventually retrieved the wheel for me and as the tyre garage was within a mile of the motorway (and I was quite close to that junction) they drove me there with my car on their flatbed truck. The manager of the garage went ashen when I explained what had happened but as the only damage was an almost unnoticeable large but gentle dent in the bodywork where the wheel had hit as it went off on its bid for freedom, they were able to fix it with new nuts and get me back on the road quickly.Extremely scary experience though. Modern tyre garages tend to do a final tighten with a wrench for safety if they’ve used the compressed air spanner - something that hadn’t happened in my case. I now always ensure this is done before I leave the premises.
Will there be even a slight difference in the ground clearance for the same car with 15 inch alloys and 16 inch alloys?
Thanks for A2A.Ground clearence depends on the wheel radius, which in turn, depends more on the tire than the wheel rim - particularly with just 1 inch difference in the rim size.The tires are typically rated as xxx/xx Rxx (Eg. 275/75 R15). Here, the first xxx (275) is the width of the tire in mm. 275 mmThe second /xx (/75) is the aspect ratio of height to width in percentage. height of tire above rim = 275 x 0.75 = 206.25 mmThe third Rxx (R15) is the diameter of the rim in inches. 15 inches = 381 mmDiameter of the wheel = height of tire x 2 + rim diameter = 206.25 x 2 + 381 = 793.5 mmRadius of the wheel = 793.5/2 = 396.75 mmNow if you go for a larger rim and / or wider tires, you could chose the tire aspect ratio such that you can come close to or match the wheel radius.For example you want a 16-inch wheel in place of the 15-inch 275/75 R15 tire with the same width (275 mm). Let's work our way backwards.Diameter of the wheel = 793.5 = H x 2 + 406.4. Or H = 193.55 mm (H = height of tire above rim)Aspect ratio required = 193.55 / 275 = 0.70 or 70.Thus, a tire 275/70 R16 tire on a 16 inch rim would give you the same ground clearence as a 275/75 R15 tire on a 15 inch wheel rim.Here's one of the many free tire calculators available online if you don't want to do these calculations yourself.http://www.miata.net/garage/tire...Disclaimer: The static and dynamic rolling radius are slightly less than than free radius calculated above due to flattening of the tire at the contact patch. Thus the ground clearence would also be slightly lower.