I have had the pleasure of driving a 2010 Oct estate for a number of years, I have just recently moved to the country and am appalled by the state of the local roads.......having already blown a tyre in potholes not to be paid out by the council.

 

The question being, I am currently running 225/40 R18 Goodyear tyres, can I fit a higher profile tyre to the stock rim to help with the potholes.

Maybe a noob question but would appreciate any help.

I swapped to 16" from 18s for the very same reason. Suffolk back roads are not great for potholes and provide little opportunity to push the limits on handling

I'm in the middle with 225/45/17s and given the state of the roads would fit the smallest diameter wheel/highest profile tyre if I could, even non potholed roads are a mess of patches and speed bumps so I never get a smooth drive.

Hmm, I have a lot of near answers to this.

 

Some tyres are more rugged than others. I had the experience, a few years ago that I ran over a brick. The front tyre, a Barum Bravuris, in 'extra load' (whatever the load numbers, eg '94', etc, was) was unmarked, but the rear, a Goodyear Efficient Grip (non-XL, as they only made the EG in non-XL, and so its load rating was approx a couple lower at, say, 92), was bruised, and both took roughly the same impact, plus or minus the higher static load on the front.

 

You can, assuming your insurance agrees, run more-or-less any sane wheel/tyre combo, but if the rolling radius goes up, you'll change the speedo reading (some will argue that's no bad thing, given the speedo error, but the speedo error on mine looks like a constant offset, and this will change it by a percentage) and raise the ride height.

 

A higher ride height raises the c-of-g, but not by much. It also decreases the odometer over-read, but not by much.

 

You may also improve the fuel economy, but not enough to stop it looking worse.

 

Tyre cost will change. You'd expect more rubber to be proportionally more expensive (away from supercar tyres) but this isn't really true. More popular tyre sizes don't go up as much as you'd think, so moving away from the tyres used on popular models is usually a bad thing (TM).

 

And then where do you get your tyre damage? Presuming that it is in the sidewalls, that raises another question. If the combination of the tread width and the 'J' dimension stretches the tyre, the sidewall will be more vulnerable to sharp objects (eg nails). If it doesn't stretch the tyre enough, it will be more vulnerable to 'pinching' damage, as is likely to be be caused by sharp edges and/or underinflation, the sharp edges of potholes being a thing.

 

At one time, you could get brochures from tyre manufacturers that included the recommended range of 'J' sizes for each tyre variety and fitting, but I haven't seen one of those for a couple of decades.

 

Now you can e-mail them and they might tell you....might...and that might be for one tyre size, which would mean it could take you an age to find out about a range of tyre sizes. over several manufacturers (although, to be fair, if you are in the centre of one manufacturer's range, you'll probably be in for all manufacturers of similar tyres, but go too oddball, and to the extremes and all bets are off).

 

Simples!

 

(It might be easier to upgrade your council.) 

Honestly your best option would be to "downgrade" to a 16" wheel or something.

 

The stock tyre size for 16" is then 205/55/16 and provides great ride comfort but doesn't feel spongy or squishy even when driving harder.

 

I'd also go for XL tyres. As above they just provide that extra strength and especially with a larger profile tyre they resist sidewall flex and improve cornering stability.

Edited 21 March, 20215 yr by Phil-E

Oh and another tip. Go for all seasons. They provide some massively improved winter grip. If you're not planning on track days etc then the slightly diminished summer performance is negligible.

 

They also improve grip on muddy conditions.