I previously upsized my tyres which are now wider since I wanted it to be more stable on the road without performing major modifications, but that decreased the diameter by 0.4%.

I thought that wouldn't make any difference but now the car body can easily touch the ground which can cause damage (I am afraid it would cause damage to the gearbox.

The other problem is that roads here are rough, they are not helping with that so I am thinking about changing the tyres along with the rims which have scratches.

Original size: 175/70R14

Current size: 185/65R14

Should I increase the rims to 15 with a slight increase of diameter by 0.4% (185/60R15) or buy new same size rims with some increase in the diameter by 2.5% (185/75R14) in order to avoid rough roads?

What is the optimum recommendation for stability and rough roads?

  • why not replace the tires with 185/70-14 and make your car legal to drive? Aug 1 '20 at 11:57
  • 1
    You haven't told us the make of car, but the optimum solution is probably "uses the manufacturer's recommended tire size, and drive a bit slower".
    – alephzero
    Aug 1 '20 at 12:43
  • It is a Hyundai accent 2015, no matter how careful you are the roads are tough, there are holes in the middle of the roads
    – EgyXDN
    Aug 1 '20 at 13:11
  • I am replacing the stock ones with wider tyres so the car can be more stable on road
    – EgyXDN
    Aug 1 '20 at 13:12
  • The sidewall heights of the two tires are almost identical, I highly doubt that is why your car is bottoming out. You have a different problem or you've created a different issue.
    – GdD
    Aug 1 '20 at 20:12

Wider tyres won't generally make your car more stable - at least not to the extent that you'd notice on the type of road you're describing. Quality makes much more difference.

If I were going to be doing any significant distance on rough roads, I'd be looking at steel wheels (as they're more resilient to damage than alloys), in the smallest diameter that will fit (most likely 14" in your case), with the largest sidewall tyres you can fit, so that the flex of the sidewall helps absorb the roughness. I'd also look for tyres with reinforced sidewalls, so they're less likely to get damage - often those sold for vans can be useful.

Source: 15 years involvement in low-budget rallying, and a number of contacts in the long-distance transcontinental rally scene.


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