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That should be about 3/4 of an inch taller in the well than stock (22.3" diameter stock 155/60/R15 vs 24" diameter with 175/65/R15)
Traction control is pretty picky, so make sure your tires are as close as possible to the same ratio as stock.
 

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Does anyone know if 175/65/r15 fit on the front of the smart 451?
The standard tire and rim sizes are 175/55R15 77T 5.5Jx15 ET22 rear and 155/60R15 74T 4.5Jx15 ET23.5 front.

The official minimum rim width for a 175/65R15 tire is 5J so a local tire fitter could refuse to fit it to the 4.5J rim.

The outside diameter of a 175/55R15 tire is (15 x 25.4) + (175 x 1.1) = 573.5mm
The outside diameter of a 155/60R15 tire is (15 x 25.4) + (155 x 1.2) = 567mm

So the ratio of the outside diameter of the standard rear tire to the outside diameter of the standard front tire is 573.5 / 567 = 1.01

1.01 means that the outside diameter of the rear tire is 1% bigger than the outside diameter of the front tire. This is the ratio that you need to keep close to.

To keep close to the standard ratio, increase the size of the rear and front tires by the same amount.

For example:

Option 1
175/60R15 rear and 155/65R15 front

Option 2
175/65R15 rear and 155/70R15 front

Option 3
185/55R15 rear and 165/60R15 front

Option 4
185/60R15 rear and 165/65R15 front

Option 5
195/50R15 rear and 175/55R15 front

Option 6
195/55R15 rear and 175/60R15 front

Option 7
195/60R15 rear and 175/65R15 front

Option 8
205/55R15 rear and 185/60R15 front

Out of these eight options, I would choose Option 3 as it provides a noticeable improvement in ride comfort, keeps the gearing close to standard, and good matching tires are available. The tire sizes in Option 7 have the biggest outside diameter, have the potential to provide the best ride comfort, good matching tires are available, however this size does raise the gearing a lot. All of these eight options will fit the standard 5.5Jx15 ET22 rear rims and 4.5Jx15 ET23.5 front rims. None of the tires should rub, except possibly slight rubbing on the front with Option 7 and Option 8. 175/50 and 185/55 tyres won't fit a 4.5J rim, and need at least a 5J rim.

Vredestein Quatrac 5 185/55R15 82H

Vredestein Quatrac 5 165/60R15 77H

Vredestein Quatrac 5 195/60R15 88H

Vredestein Quatrac 5 175/65R15 84H
 

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I put 185/65R15 on the front on 5 inch rial alloy rims, which is supposedly the max a 5 inch rim will safely take. A 4.5 inch rim should handle the 175/65R15. But you probably will get rubbing, certainly on a bounce, since the diameter difference is only 0.5 inches, and half that for the radius. I put EV springs in last weekend and it raised the car enough to solve my rubbing issue. I’m running 205/60R15 on 6 inch rims in the rear. I had no clearance issues there. The stock 5.5 inch rear rim should safely take a 195/60R15. That combination would give you 24 inch diameter up front and 24.2 inch diameter in rear. You’d be hard pressed to get much closer. I like the extra width of the tires. And the extra height of the sidewalls provides for a smoother ride, as I have discovered with bridge joints.
 

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Discussion Starter · #6 ·
I know some on here have put 175/55 on front stock rims without issue, I was just looking for a bit more rubber between road and rim.on a 175 /65/15 diameter is 24in the same as those who run 185/60/15 in the front and experience minor rubbing only on Corning and hitting a bump. Only difference is they run a set of rear rims on the front I’m trying to stick with stock fronts.
 

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I’d try to avoid any rubbing. At 60 mph, that tire is doing a lot of spinning and even a momentary bump will seem like a lifetime. I can see traces in the front wheel wells from before I installed the EV springs.
 

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How much rubbing are we talking about?😂
Enough to burn off one of the splash guard retainers and burn away a fair amount of the leading edge of the fender lip in a matter of less than 100 miles. Get a nice rock wedged in there and I can imagine the fun.
 

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I know some on here have put 175/55 on front stock rims without issue, I was just looking for a bit more rubber between road and rim.on a 175 /65/15 diameter is 24in the same as those who run 185/60/15 in the front and experience minor rubbing only on Corning and hitting a bump. Only difference is they run a set of rear rims on the front I’m trying to stick with stock fronts.
Some of the tires that can be fitted to 4.5J rims include 175/55 and higher aspect ratios, and 185/60 and higher aspect ratios. 175/50 and 185/55 need at least a 5J rim.
 
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