S40 V40 Cars: Will changing tyre size provide a better ride

[Milesk]

We have a v40 cross county d4 polestar running on 225/40/19 and we have put up with the ride quality for 2 years - really harsh ride, close to the point of considering selling the car.

Most v40,s come with 225/50/17 as standard,

What is the general opinion, would this help our car ride by changing to a 225/50/17

Thanks

[BlueDevil]

Definitely.
I remember on the old car (not Volvo), which had 16" stock and I test-drove the 17" and 18" options. Man, what a difference! The amount of shocks that rubber absorbed is remarkable!

[ITSv40]

'er indoors has a Mini Cooper on factory fitted 15 inch rims and the ride quality is fine. It is a recognised mod within Mini circles to change 17inch rims for 15's as the ride quality is so much better on the smaller wheels.

[BlueDevil]

From 225/40/19 to 225/50/17 there's 2.25cm more sidewall between the road and the rim at any given time. That's 25% more sidewall, including the air in the tire. That absorbes a lot more bumps. 225/40 is a low-profile tire in my book, and while it look good (even amazing) on some cars, it is not comfortable at all.

A SUV with low-profile tires looks ridiculous, IMO. Much more ridiculous than a BMW (for instance, a 5-series) with 55/60/65 profile tir. That's funny looking, but better than a SUV with 30/35/40 profile.

However, aesthetics aside, in my experience anything under 50 profile is uncomfortable for an old fart like myself (1975). As a 20-yr-old I would go with 30-profile because who cares about comfort if you look badass, but since then I've come to appreciate comfort a bit more.

You'll notice any change in profile up from your current 40. Hopefully somebody on this forum has that profile of tires and lives near you so you can sit and see before you buy, but you'll notice the difference immediately.

[Milesk]

Thanks for the replies so far - looks like changing the tyres would be a good move

[Sotosound]

I trust that you're also thinking about changing the wheels to 17" and ensuring that the rolling radius remains unchanged so that your speedo won't over-read or under-read.....

Also, you'd need to check with your insurance company about making a change to the wheels and tyres.

[DaveNP]

Difference in rolling radius for those sizes is less than the difference of a worn vs new tyre.


Let's not diss the 19s too much, there wil be someone out there who wants the look and Milesk can flog them to offset the cost of the 17s

[PRainbow]

Changed my C30 18” rims with 45 profile tyres to 17’s with higher 60 profile sidewalls. Much nicer ride!

[Kev0607]

Originally Posted by Sotosound

I trust that you're also thinking about changing the wheels to 17" and ensuring that the rolling radius remains unchanged so that your speedo won't over-read or under-read.....

Also, you'd need to check with your insurance company about making a change to the wheels and tyres.

I don't think you need to if the ones you're putting on are an original option with the car.

Originally Posted by Milesk

Thanks for the replies so far - looks like changing the tyres would be a good move

A 17" tyre won't fit your existing 19" rim, so you can't just change the tyres. You need a set of 17" alloys & a set of 17" tyres don't forget.

You'll notice a massive difference though. 17" will offer you a much more comfortable ride.

[BlueDevil]

Originally Posted by Sotosound

I trust that you're also thinking about changing the wheels to 17" and ensuring that the rolling radius remains unchanged so that your speedo won't over-read or under-read.....

Also, you'd need to check with your insurance company about making a change to the wheels and tyres.

Of course, of course. Every make/model manufacturer recommends a few options, like for my XC60 there's Volvo recommended sizes in 17, 18, 19 & 20". If you do the math, the difference in rolling radius is within 4mm, and I belive the limit is 5% as to keep the speedometer correct, so 4mm is well within that limit.

So for my XC60 Volvo says:

235/65/17 (rr=737,30mm), sidewall=152,75mm
235/60/18 (rr=739,20mm), sidewall=141,00mm
235/55/19 (rr=741,10mm), sidewall=129,25mm
255/45/20 (rr=737,50mm), sidewall=114,75mm

If I want a wider tire, say 255, but don't want to go 20" (comfort and all), then with a little Excel and some googling you get you can use also:

255/50/19 (rr=737,60mm), sidewall=127,50mm
255/55/18 (rr=737,70mm), sidewall=140,25mm
255/60/17 (rr=737,80mm), sidewall=153,00mm

As for the comfort, I wouldn't go with sidewall under 130 - that's 2cm less than the (most comfortable) 17" sidewall is, so my personal favorites would be 255/55/18 or 235/55/19. Which is what I'm aiming for for summer, while I intend to have a set of 17" for winter since the elevated sidewall helps keeping the rims above the snow/ice that can sand them.