# Pothole resistance: what matters besides tire sidewall height?

I am buying a new car. The wheel options are 225/55-19 and 225/65-17.

My old car has 195/60-15 wheels.

I live in a region of the world with lots of potholes. So, the general recommendation is to go with the higher tire sidewall, thus the 17" wheels.

However, if you do the math, I'm going from a 117 mm sidewall to either a 124 mm with 19" or 146 mm with 17".

I'm "relatively comfortable" hitting potholes with my old sidewall. Does that mean that I can get the 19", and still get a slight improvement in pothole resistance? (Assuming the same tire model in all cases for the sake of simplicity.)

(If that matters - mass of the old car is 1200 kg / 2600 lb, new one 1600 kg / 3500 lb, so the new one is 30% heavier.)

• Welcome to Motor Vehicle Maintenance & Repair! – Pᴀᴜʟsᴛᴇʀ2 Apr 20 '18 at 19:32
• What Matters besides? Is your ability to dodge the potholes. – Moab Apr 20 '18 at 19:52
• I'm not convinced by your math. A tire's sidewall height - the distance from the wheel rim to to pavement surface - usually reduces as the wheel size increases, in order to maintain the tires' original circumference, and therefore, the accuracy of the car's speedometer. If 225/55-19 and 255/65-17 tires are about the same diameter, the tires will necessarily have a shorter sidewall height than your current car, as more of the wheel rim-to-pavement distance will be taken up by the larger wheels. In any event, I'd suggest you choose a smaller diameter wheel rather than a larger. – DavidSupportsMonica Apr 20 '18 at 21:31
• @David the 19" rims have 2 inches more in diameter than 17", or 51 mm. The difference in sidewall height between 225/55 and 225/65 is 22 mm, but this is on a radius. Thus the total difference in wheel diameter that the tire brings is 44mm. Subtract that from the 51mm added to the rims and you get that the difference in wheel diameter is only 7mm - less than 1%. – Leonid Shevtsov Apr 23 '18 at 8:03

Another factor to consider when looking at pothole resistance is the weight of the wheels.. typically 19" rims will weigh more than the 17" equivalent and as this is unsprung mass the only thing providing cushioning for all that extra weight when hitting a pothole is the flex in the tyre sidewall, which already have less flex due to being lower profile so not only are any occupants of the car going to get a harder hit in pothole encounters the wheel does as well - and speaking as someone who had two 19" wheels crack from hitting potholes it's not just ride quality that is affected but your wallet might not do so well either!

Additionally the reduced sidewall height will mean that shallower potholes will have potential for impacting directly on the face of the rim than would be the case on the 17" wheels.

!9" wheels might look great, and they perform well on a good quality surface but if potholes are at all common where you live then they are an uncomfortable and expensive liability IMO.

Do not get the 19" tires, I drive a 4,300 lb sedan with 19" low profile tires in an area with lots of potholes and I've had to replace 4 tires and rims this year alone due to even the smallest pothole hits. it's like a game of dodge the potholes, takes the fun out of driving. Can't wait to return the lease. Thankfully I have tire insurance, but not worth the headache of getting them replaced every so often

• Welcome to Motor Vehicle Maintenance & Repair! – Cullub Aug 28 '18 at 3:49

Don't.

I have 225/65-17 tires and I do indeed dodge the potholes. However, if I fail to dodge, it won't be a total disaster, assuming the pothole is a typical one and not the worst possible pothole.

Before the current SUV, I had a car with 185/60-15 tires (if I recall correctly). Potholes felt a lot worse in that car.

The 225/55-19 tires are just for show. There is no reason to select them if you drive in an area with lots of potholes. Yes, they may be better than your previous 195/60-15 tires, but still, if you have an even better option, why choose the worse?

My car had 235/55-18 tires as standard in the "better"-equipped models. I didn't choose the "better"-equipped model, because I consider it as "worse"-equipped.