Can Different aspect ratio tires causing car to shake?

Pretty much the title. I got new wheels with tires already on them and had them installed at a local tire shop. Afterwards I got an alignment and balance as well for good measure. However afterwards I noticed that going above 60 mph the steering wheel starts vibrating and the steering wheel is also slightly crooked to the left. This made no sense seeing that the wheels and tires are brand new and the car never shook at any speed before installing them.

2 of the tires are 235/35/R19’s and 2 of them are 235/40/R19’s. Upon further inspection, I noticed that the shop put both 235/40s on the left side and both 235/35’s on the right side. (Face palm). Is this for sure what’s causing the shaking at higher speeds issue? My apologies, I know nothing about tires

Another question: after I switch the wheels so they’re the same dimensions on each axle, do I need to rebalance and do a new alignment?

Could be, first time I’ve seen different sizes fitted L/R instead of F/R.

To be fair though I didn’t tell them that 2 of the wheels had a different aspect ratio but it slipped my mind but you’d also think they’d check before installing them…

I guess my main question is; should i just switch the wheels to the correct locations myself? Or do i have to get the car re aligned and re balanced? In that case I’d take it back to the shop.

I didn’t do it myself in the first place because i only have a manual turn lug nut wrench but the shops have a lift and impact gun and can do it much faster and easier and rather would pay the $30 or so for mounting the wheels

New or new to you?

Brand new ordered online

Return with the tires in the wrong position, perhaps they will check the alignment free of charge.

It would have been practical to balance the wheels before installing them on the car. But who sells mounted tires that are not balanced?

Do you have an AWD vehicle?

The source of the shaking can be several things:

  1. The wheels are not centered on the hubs. It is not uncommon for aftermarket wheels to pilot on the studs rather than the center hub. They make hub rings for that.

  2. The tire/wheel assembly is not properly balanced. It is not uncommon for some places to think static balance is enough - it isn’t! Tires and wheels need to be dynamically balanced.

  3. The tire wheel assembly is out of round. No amount of balancing will fix that. You need to have a specialized machine to figure out if that is the case - a Hunter GSP9700 RoadForce balancer. Hunter: Find Equipment.

And, No! The location of the wheels/tires, nor the aspect ratio of the tire cause vibrations.


If this car is your Mustang, the steering wheel being off is the different diameter tires being on different sides. As for the rest, @CapriRacer covered all the likely scenarios #1 is a big one as Mustangs are sensitive to being centered on the hub.

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You ordered tires with different aspect ratios on purpose? If that was your intention, what is your plan?
Does your manual mention this? Is car made with 4 identical tires?
Some cars have 40/18” on front and 35/19” on rear, for example.
Having same diameter with 2 very close ratios seems like a recipe for screwups.

Lets see here - person orders wheels and tires - has them put on vehicle - notices a vibration that was not there before - goes on line to a forum instead of calling or returning to the shop first .

OK Fine. :thinking:


Your ABS won’t like different OD tires.

The tires are different diameters.
Even with a 2WD car this side-to-side difference will put stress on the differential.
That could also be the source of vibration.
And I’m not surprised it pulls to one side, due to a difference in rolling resistance.


I bet it is an Audi.
The tire tech missed it. The alignment specialist missed it.

I think you’d lose that bet.

Look at the OP’s posts, he bought a 2011 V6 Mustang recently and that would be an appropriate tire size for that car… well the 40 series tires would be. Not sure why he’d split the pairs with 35s and 40 series. Maybe to get a little rake in the stance.

My 66 mustang had 195/70/14image

My 2013 Mustang sits on 275/40/18s, what’s your point?

Suggest to first place identical tires on each axle. If you still got the shakes, go from there. As mentioned above, it seems odd a mounted wheel would be sold (the entire combo new presumably) without it already being properly balanced. But anything’s possible I guess. No harm to rebalance them.

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these are great!

i think i must disagree with this, however. as @circuitsmith said, the wheels have different final diameter, i believe. if the width is the same, but the aspect ratio is different, then the diameter = 2 * (hub radius + aspect ratio * width) will be different too.

if wheels are different diameter left and right, that will cause a pull to the side, and likely a wobble too. no?

hope this is helpful.