[Closed] Car tyres question - why do large tyres have worse ride characteristics

Bigger wheel = smaller tyre with less air volume and stiffer sidewalls.

It's the profile.

The outer diameter of the tyre is roughly the same for a car model. So when you buy a bigger wheel the sidewall height of the tyre is reduced to maintain the similar diameter. This results in less cushioning as there is less tyre to absorb impacts.

D'oh - ok, seems obvious now.

I drive a Volvo XC90, and the higher the spec, the larger the alloys they put on. I don't want bloody low profile tyres on a 4x4 😕

Bimbler - Member

I get the noise bit but just you'd of thought that larger tyres would be betterer than smaller tyres on rough surfaces just as 29er tyres smooth out the trail compared to 26er's?

It doesn't say 'larger tyres' - it says larger (big) wheels.
Bigger wheel generally = lower profile tyre & a tyre with a lower profile (not very high sidewalls) tend to be stiffer & less comfortable.

But, big wheels are fashionable because peoples love driving them into the kerb (like my Wife does with the 17" polished wheels on our family wagon)..... 🙄

'Big wheel' refers to the profile, not the outer diameter :roll:.

I think we've answered the OP's question, but given the usual tangent, one of the advantages to me of my car being bottom of the range spec is it comes with small steel wheels and decent height tyres - not only better ride, but also significantly cheaper to replace (I actually went with slightly narrower tyres when I replaced them on advice of the tyre place I used - cheaper, but the tyres I have are supposedly specced for my car as they're in the pressure chart in the handbook, and the grip/handling with them is still fine).

When I was looking at buying my current car, most of those I was considering were fairly high spec but also with a sport pack which gave big wheels and very low profile tyres (along with the roof rails which were part of my spec) - I'd budgeted for a set of steelies and normal tyres like the ones I now have as that really wasn't something I wanted. Surprised more people don't do that, as by the time you've replaced 2 sets of tyres you've saved money.

My old Passat B7 had 17" wheels with low-profile tyres, and it rode harshly and noisily. The car also looks under-wheeled.

My new B8 has the same 17" wheels but a bigger tyre and the difference is amazing; it feels like a much more grown-up car as it's quieter, smoother and somehow better at speed on the motorway. The wheels also fill the arches and look much better.

Although you get more cushioning with a tyre that has a taller side wall, a flip side is that you get more flex in that side wall as well, particularly from side to side on cornering and cambers. The tyre tread might stay in the same place on the tarmac, but the car above it can shift from side to side as the tyre flexes. A result being that the car body is moving about can potentially feel like its not tracking the road correctly and infer to the driver its less stable on the road in certain circumstances. Imagine having your bike tyre at a soft pressure - you can feel that flex and the tyre not track the trail correctly or the way you want it. Same is true of car tyres.

The same can even be said for tyres of the same size, but different brands ... I had pirellis on mine, and it wandered about feeling like it was bobbing from side to side as you went along, changed to kumhos and the car is noticeably more planted with the side to side bobbing gone - all down to the sidewall flexing.

So to the OP ... taller tyres can mean more flex, and can feel like car instability on cornering which people translate to poorer ride characteristics.

Car reviewers are more likely to push their driving of a car to the limits where you could notice these things and so comment on them to justify their column space, where as a lot of people wouldn't drive like that and just would prefer a comfy smooth ride.

Surprised more people don't do that, as by the time you've replaced 2 sets of tyres you've saved money.

Are you really surprised by that? I mean, really?

One of mynew car checks is tyre size.

Don't get the whole car thing so usually stick with small hatchbacks that are cheap to get me to work.

Didn't check the last one and the sporty alloy wheel look the previous owner went for, meant around £100 for a tyre, current one is nearer £60 a tyre as it has more normal sized wheels.

Certainly makes a difference when it comes to paying the bill for new tyres and there is pretty much no differences in handling - certainly not with a driving style that doesn't risk killing myself or another road user as seems popular with local SUV drivers.

Cars are a lot heavier these days, so you need stiffer suspension to manage the body roll and other effects of a big heavy body. Add to that lower profile tyres 'cos they look cool! and you've got a deterioration in the ride quality.

Nothing wrong with higher profile tyres. They are a bit squidgier in terms of lateral flex, but F1 cars seem to do OK on high profile tyres so not an issue for handling. It's just high profile tyres are just not cool bra!

[quote=chiefgrooveguru ]Are you really surprised by that? I mean, really?

No - you're right - clearly there's a reason they fit big wheels with rubber bands round the outside as most people are more bothered about the image.

And in the bike world we're seeing a resurgence of 650 "plus" to fit higher volume tyres into nominally 700c frames.

No - you're right - clearly there's a reason they fit big wheels with rubber bands round the outside as most people are more bothered about the image.

I prefer a lower profile tyre for the improved handling they give. Combined with the stiffer suspension my cars have compared to the basic spec ones it makes them more enjoyable to drive on a twisty road.

I'm not too bothered about the image, in winter I swap the wheels for winters which look gash. There's a marked difference in the handling between the summer and winter wheels and a large amount of it is down to sidewall flex.

If you don't particularly enjoy driving then it's not a difference you'll appreciate, and a more comfortable tyre will be more important. It does baffle me why the low profile tyre has taken off on luxo barges and, in particular, 4x4s.

I went from 15" alloys to 17" steel wheels on my Volvo 940. Looks miles better but blimey you can feel the edges of those bumps!

Looks fantastic though. 😀

I drive a Volvo XC90, and the higher the spec, the larger the alloys they put on. I don't want bloody low profile tyres on a 4x4

My old ranger with the high profile tyres was a big wallowy barge that was super comfortable to be in.
Not like my beemer with the stupid 19" runflats 🙄
(And no, I didn't spec them)

I switched from 225/45 17 Summers to 205/55 16 Winters about a month ago, I can't really tell any difference in the ride or handling. They sure don't look as nice though!

[quote=munrobiker ]If you don't particularly enjoy driving then it's not a difference you'll appreciate, and a more comfortable tyre will be more important.

I enjoy driving a twisty mountain road as much as anybody, but if by "enjoy" you mean throwing a car down the road as fast as possible and exploring the limits of grip (which is the only way I can see you'd notice the difference in handling) then that's the sort of thing I reckon should be confined to a race track. As much discussed on here, enjoyment from driving isn't all about how fast you can take the corners - plenty of fun to be had driving a Fiat Panda.

Though let's be honest, most people don't explore the limits of grip and would appreciate the extra comfort and for them it is all about image. Personally I drive on normal UK roads which aren't always in the best condition and even with my "high profile" (they're still 55 profile which is the highest profile specced for my car!) tyres I've still managed to ding one of my rims - though I also occasionally drive on gravel tracks, hence not wanting rubber bands.

I live in a rural area surrounded by farms and single lane roads, where you have to drive up the bank or into a muddy lay-by to give way to other vehicles, riddled with potholes. I have a cruddy old Astra Estate with "normal" tyres and my wife has a new Polo with low profile "sports" alloy wheels and tyres.

With her car we are having to get the tracking done 2-3 times a year and it is horrible sat in the passenger seat and hitting all the rough edges of the road, plus she goes through tyres 2-3 times more frequently than me with uneven wear and punctures.

I can see the merits of low profile tyres on a sports car where handling is everything, but too many normal cars have them these days purely for the look.

Lower profile tyres don't actually provide better handling. They give you a sense of 'handling on rails' but in actual fact higher profile tyres (to a point) will provide better grip and traction, and ultimately grip is the holy grail. You only need handling when you run out of grip.

When I got my T5 it came with 18" alloys and low profile tyres. I switched to std 16" steed (although material itself doesn't matter I suppose l) and the ride quality was so much nicer. Less noise, less crashing over bumps & potholes and it also stopped it tram lining on the motorway in the grooves worn by lorries.

Another complainer here about higher spec cars having larger wheels and lower profile tyres. I have been put off such models and got into discussions with dealers about putting more normal wheels/tyres on.

See - it isn't just me then! Seriously a set of smaller steelies isn't that expensive and the outlay more than made back with cheaper tyres.

small diameter wheels and higher profile tyres are for winners. it makes everything you can measure better including ride, steering, handling, nvh, mpg etc etc. its crazy that we are willing to throw away all those good things for looks

Last time I was changing cars I thought it would be easy. Just wanted a largish petrol hatchback. Not sporty but a bit more power than base models to match my old Mondeo 1.8 petrol. Wanted a real (not electric) handbrake. Didn't want low profile tyres as local roads are potholed, rutted, crap.

After eliminating cars with electric handbrakes and low profile tyres the choice was smaller than I thought. It's almost a rule that going a model or two up from base means low profile tyres.

Same here,16" is plenty big enough for most cars, nice comy 55 profile, and you can get high end tyres without breaking the bank.

My T5 has 17" steelies and 16" summer wheels.

Recently had a ride in a friends T6 bling mobile running 19" rims and the ride was harsh. Not quite as harsh as the GF's lowered MX5 when running 16" alloys in summer, mind.

The stiffer sidewall on a lower profile tyre helps keep the rubber more square to the road hence more grip. You also get more steering feedback, for better or worse. And more road noise and less comfort. I've had two cars which have been identical bar one having 195/65 R15 and the other 215/45 R17. The latter has a lot more grip on the same brand of tyre but is noisier. It probably does fewer MPG too. It's certainly been kerbed more often!