Why do we have to have low profile tyres to look "sporty"?

[Shakermaker]

Flibble said:

How many cars have such large brakes that they couldn't fit a rim with a 45 profile tyre over? I'll give you a hint, it isn't many. Far more common is the rather daft look of a ~250 mm disc lost inside a 19" wheel.

What is the "45 profile" a percentage of though? 45% of 300mm or 45% of 225mm?

[Zoon]

Probably the same reason we like women with massive breasts.

[Flibble]

Shakermaker said:

Flibble said:

How many cars have such large brakes that they couldn't fit a rim with a 45 profile tyre over? I'll give you a hint, it isn't many. Far more common is the rather daft look of a ~250 mm disc lost inside a 19" wheel.

What is the "45 profile" a percentage of though? 45% of 300mm or 45% of 225mm?

Doesn't really matter in practice as a car with 300mm wide tyres will likely have larger rims to start with. If you assume that the lowest profile tyre a car would realistically be sold on OEM is 35 profile, you're only looking at dropping 1-2 inches of rim diameter to get to a 45 profile, which is generally easily doable while still clearing OEM brakes. Bear in mind a 17 inch wheel will clear a 330mm disc, which is larger than the majority of cars are running already.
If you have bonkers aftermarket discs, then yes it might be an issue, but that's not the case for the cars being discussed here.

[Alex_225]

Dog Star said:

Alex_225 said:

For the right car, like the one shown in the first post, it can look great with chunky, wide tyres but it's partly down to the stance and style of the car. A proper 4x4 with big tyres and wide stance can look awesome but I do think that a sporty car can often look better with more alloy and a bit less tyre, within reason for road use that is.

That's the point I'm trying to make though - I don't necessarily think that the "sporty" cars do look better on the rubber band tyres; I bet a 5 series BMW would look ace with wheel like in the first pic.

I mean don't get me wrong, I'd like to see what an M5 would look like with a slight drag/muscle car look to it. I'm sure that style could lend itself to a few cars out there I admit. There's a few Twingo 133 owners who have gone from the standard 17" wheels to 15" rims which look more track focused and pretty cool.

By contrast though, I think the 18" rims on my other half's CLS350 look pretty spot on without being a silly size, the ride is excellent. Would be intrigued as to what it would look like, so feel free to photoshop it!

[Prinny]

I think this is what Flibble is implying - the triumph of marketing over engineering.

[Flibble]

Nanook said:

What?

First, show me a car with 300mm+ wide wheels, that's got clearance around the brakes to go down a size or two.

I'm not sure I can show you a car with 300mm wheels tbh, not much comes with something that big from the factory.

Nanook said:

Bear in mind a 17" wheel will clear a 330mm disc? Well, that depends on a whole bunch of things, doesn't it? The discs on the front of my car are 324mm. By the time you wrap the 4-pot calipers around them, you need 18s to clear them.

Well obviously there are braking setups with larger than average calipers, what I meant was it is possible to fit 330mm discs (and calipers) under a 17 inch wheel. If an OEM had a design spec of 17 inch wheels and 330mm discs they would make it work.

Nanook said:

Bonkers aftermarket discs? It's never the discs that are the problem. It's the caliper and carrier. You can't just take the discs off your car, and fit bigger ones without changing anything else.

No st sherlock. I meant an aftermarket brake kit featuring larger discs. Surely that was obvious? Or is this another case of PH pedantry gone mad?

My point was, and it was mentioned above. If you take a typical road car (with or without a "sport" pack featuring huge wheels) there is no reason you can't run it on 45 profile tyres given typical brake sizes. Saying you need oversized wheels and 35 profile tyres to clear the brakes just doesn't apply to almost anything with factory spec brakes.

[Flibble]

Nanook said:

That car never came from the factory with those wheels though.

Someone's chosen to modify their own car. So not really relevant.

Plenty of OEM examples:

[TWPC]

Nanook said:

Prinny said:

I think this is what Flibble is implying - the triumph of marketing over engineering.

That car never came from the factory with those wheels though.

Someone's chosen to modify their own car. So not really relevant.

But to illustrate Flibble's point: a RR Sport on factory fitted 22 inchers (and this on the long termer run by Car in 2015-16):

[RicksAlfas]

Dog Star said:

Is it just me?

No. Me too! I love a big gumball tyre.
None of these would look good with low profile tyres, and so many modern cars would look better with some more profile too. I'm hoping one day the roads will be so bad that this trend will disappear and we will get some proper profiles back.

[TWPC]

Here's a decent sports car's wheel.

[RedSwede]

With the exception of the Merc above, all the high profile stuff looks good on wheels with low (or more positive, however you think of it) offset. Modern cars have very negative offsets, so rim and/or dish isn't really possible (presumably to put the bearings/steering stuff in the centre of the wheel). That Challenger has crazy arch extensions.

It also typically requires minimal arch gap to look good (IMO) - again, not something styled into modern cars.

I think the Challenger looks great, and am a big fan of some rim/dish. But just taking a random modern car and some small wheels, you ain't going to achieve that look. The whole current fashion of car design is wrong for it, not just the size of wheels.

[Flibble]

Nanook said:

That's a rear wheel.

I take your point, but if you look at the front brakes on that car, there's not nearly as much clearance as that picture shows.

And I'm assume you're not proposing fitting smaller diameter wheels to the back of the car, than are on the front?

Interesting point though. Some cars have larger diameter wheels on the back, has anyone ever built a car with larger diameter wheels on the front before?

Front to rear brake difference is usually about an inch of diameter, give or take? Still going to be acres of space on that fitment.

I've heard of some slightly larger front wheels (Audi with the RS3), but only width, not diameter.

[Dave Hedgehog]

RicksAlfas said:

No. Me too! I love a big gumball tyre.
None of these would look good with low profile tyres, and so many modern cars would look better with some more profile too. I'm hoping one day the roads will be so bad that this trend will disappear and we will get some proper profiles back.

so a cobra that will kill you because of its terrible tyres, a lambo that will catch fire before you can hit 50mph and a wafty boring barge designed for 80 year old people who live in Florida


i will keep the ultra lows then if thats the choice

[RicksAlfas]

Dave Hedgehog said:

so a cobra that will kill you because of its terrible tyres, a lambo that will catch fire before you can hit 50mph and a wafty boring barge designed for 80 year old people who live in Florida


i will keep the ultra lows then if thats the choice

No sense of adventure!

[MC Bodge]

Tyres (and suspension) should be able to absorb typical bumps and be able to deform to maintain good contact with the road surface. For comfort and for performance.

What we have now is many vehicles that have tyres, suspension or both that are either not fit for the purpose of driving on or performing their best on UK roads.

[MC Bodge]

Nanook said:

MC Bodge said:

Tyres (and suspension) should be able to absorb typical bumps and be able to deform to maintain good contact with the road surface. For comfort and for performance.

What we have now is many vehicles that have tyres, suspension or both that are either not fit for the purpose of driving on or performing their best on UK roads.

Those 2 criteria are very very different, and optimising for each one individually would give very different results.

I know this. My point was that a rock hard ride and little volume and bump compliance does not = good/optimal road performance or ride.

[legless]

Interestingly, when I worked for one OEM, we ran a competitor evaluation fleet.

A few times, we had examples of the 'comfort' and 'sport' trims of cars simultaneously that were otherwise identical. Think a 530d SE and a 530d M-Sport, and a A4 SE and a A4 S-line.

Without exception, we could consistently set faster times on pretty much any test circuit with the 'comfort' trim. The spring and rebound rates on the suspension were so much better judged, and the higher profile tyres were better at absorbing imperfections in the surface, the net effect being that the tyre was in contact with the road surface more of the time.

[MC Bodge]

legless said:

Interestingly, when I worked for one OEM, we ran a competitor evaluation fleet.

A few times, we had examples of the 'comfort' and 'sport' trims of cars simultaneously that were otherwise identical. Think a 530d SE and a 530d M-Sport, and a A4 SE and a A4 S-line.

Without exception, we could consistently set faster times on pretty much any test circuit with the 'comfort' trim. The spring and rebound rates on the suspension were so much better judged, and the higher profile tyres were better at absorbing imperfections in the surface, the net effect being that the tyre was in contact with the road surface more of the time.

Interesting, and I suspected as much.

Can we assume that the car was designed with the standard suspension in mind and then had "sport" suspension as a sort of placebo, because hard is perceived as fast?

[PhillipM]

280E said:

I'm sure many PH-ers will remember when /70 was considered 'low-profile'

It still is, someone just tried to sell me some 235/85's when I run 70's and asked me why I run ;such a low profile?'

[Kawasicki]

legless said:

Interestingly, when I worked for one OEM, we ran a competitor evaluation fleet.

A few times, we had examples of the 'comfort' and 'sport' trims of cars simultaneously that were otherwise identical. Think a 530d SE and a 530d M-Sport, and a A4 SE and a A4 S-line.

Without exception, we could consistently set faster times on pretty much any test circuit with the 'comfort' trim. The spring and rebound rates on the suspension were so much better judged, and the higher profile tyres were better at absorbing imperfections in the surface, the net effect being that the tyre was in contact with the road surface more of the time.

That is weird, as usually a sports tyre has more grip than a comfort tyre. The chassis tunes on the sports versions must have been dangerous to drive on a typical bumpy country road, under damped to the extent that they were unable to absorb imperfections.

I must say I’m sceptical.