Are cars over-tyred today?
Discussion
Low profile tyres need to be wider as they often take a load more "getting up to temperature". Thus when cold need to have extra width to stop chumps sliding off the road larging it when cold.
The last thing you want on a road car is a set of touring car alloys (which are so in fashion). They take ages to get some heat into them, have very stiff sidewalls....which leads to a more soggy suspension setting from the factory, are bloody expensive and if you drive like a t
t, wear like hell.
The way to go is to run stiffer suspension than a road car and more profile and a harder compound. On road cars, this provides better handling and wear. £/fun, they are the winner.
If you are overheating your tyres, go for a less flexible design. Lower profile, stiffer plies/different plies and run a softer compound from the start.
It's totally about image and not about performance. Unless you are talking cars tuned to the degree that "normal" rubber is having a hard time. Lambo's etc.
If I had a BMW mini cooper S, for example, I'd stiffen the suspension right up, fit stiffer springs and wind the shocks up, I'd then stick with 15 tyres, perhaps going to 14's, assuming I could clear the brakes and then it would go better than the idiot bands I see out there.
But then again, the average Joe isn't going to be driving the thing on the limit.
The last thing you want on a road car is a set of touring car alloys (which are so in fashion). They take ages to get some heat into them, have very stiff sidewalls....which leads to a more soggy suspension setting from the factory, are bloody expensive and if you drive like a t
t, wear like hell. The way to go is to run stiffer suspension than a road car and more profile and a harder compound. On road cars, this provides better handling and wear. £/fun, they are the winner.
If you are overheating your tyres, go for a less flexible design. Lower profile, stiffer plies/different plies and run a softer compound from the start.
It's totally about image and not about performance. Unless you are talking cars tuned to the degree that "normal" rubber is having a hard time. Lambo's etc.
If I had a BMW mini cooper S, for example, I'd stiffen the suspension right up, fit stiffer springs and wind the shocks up, I'd then stick with 15 tyres, perhaps going to 14's, assuming I could clear the brakes and then it would go better than the idiot bands I see out there.
But then again, the average Joe isn't going to be driving the thing on the limit.
Edited by Shoot Blair on Thursday 15th October 00:12
I'm surprised no one has mentioned power assisted steering. The only reason these cars are able to wear such big rubber, and be remotely driveable at slower speeds or parked is because all cars even the humble 500 has PAS. I know when my last A3 broke down a 10p plastic part on the clutch, and had to be pushed the car was virtually unsteerable without electrical assistance, I was told the whole front suspension tyre geometry combo was such that it could not be driven at slow speed without PAS. The tyres on my 1.9 205 GTI 16" if memory serves would probably be classed as lightweight by today's standards.
I'd have to agree that modern cars being over-tyred is probably more due to fashion (195-wide 19" wheels would just look silly 
) than a 'bigger tyres=more grip=safer' attitude. I can't see the advantage unless you have a lot of power which you really struggle to put to the ground - wide tyres have plenty of negative handling aspects including tramlining, increased tendency to aquaplane on standing water, being hopeless on loose surfaces or snow. Not to mention the reduced feel (as said above) from everything having to be power-assisted to cope with the extra load.
I have 195/50-15" on the MX5 and 215/45-17" on the Legacy and wouldn't want to go wider or lower profile on either of them - in fact there are plenty of roads I drive on where I'd often prefer a larger profile.
) than a 'bigger tyres=more grip=safer' attitude. I can't see the advantage unless you have a lot of power which you really struggle to put to the ground - wide tyres have plenty of negative handling aspects including tramlining, increased tendency to aquaplane on standing water, being hopeless on loose surfaces or snow. Not to mention the reduced feel (as said above) from everything having to be power-assisted to cope with the extra load.I have 195/50-15" on the MX5 and 215/45-17" on the Legacy and wouldn't want to go wider or lower profile on either of them - in fact there are plenty of roads I drive on where I'd often prefer a larger profile.
Edited by GravelBen on Thursday 15th October 06:19
My Mk2 Golf had 155s but the Clio had 185s as standard. Given that they're FWD the extra rubber certainly left you with cleaner pants in the wet.
In SA for a wedding earlier this year, the other bestman hired a Mk1 Golf (still being built over there). It still has no PAS and the big girl's blouse spent all the time bhing that it was so hard to turn the wheel... despite them sporting only 155s.
In SA for a wedding earlier this year, the other bestman hired a Mk1 Golf (still being built over there). It still has no PAS and the big girl's blouse spent all the time b
hing that it was so hard to turn the wheel... despite them sporting only 155s.ian_c_uk said:
My Mini Clubman has 15's with tiny rubber, and is excellent fun, with only 120bhp.
IMO the best driving N/A MINIs are on the boggo 15s and 175/65s. Gives a fluency and purity to proceedings that eludes most if not all modern mainstream cars, almost in a French '90s warm/hot hatch sort of way.Shoot Blair said:
Low profile tyres need to be wider as they often take a load more "getting up to temperature".
You're talking about racing: the effects of tyre temperature in normal road use are negligible.The big factor with wide, low-profile tyres is simply that they grip well, but when they do let go, they let go much more abruptly than narrow, tall section tyres.
They're basically designed for numpties: manufacturers make the assumption that 95% of drivers wouldn't have the skill to react correctly when a car starts to slide, therefore they give them enough grip that they never actually reach that part of the tyre's performance envelope.
Of course, these days, we now have computers that can sort it out even for the numpties, but I guess there's no point in reverting to tyres that allow you to drift if the computers don't.
OK. Are modern cars over-tyred. i.e. Do they have too much grip?
Answer: No. They can't have too much grip. Have you seen how crap at driving most people are? These tyres are saving their lives on a daily basis! OF COURSE extra grip is a good thing. Whilst it may spoil cornering fun for those with the inclination it also provides vastly superior braking performance. Coupled with ABS this probably saves more lives than all the other road safety innovations combined.
As to the cost of the rubber? Well, hell. If it saves your life isn't it worth it? And competition is now making these wider, lower profile tyres far cheaper than they were ten years ago. When I first bought a full set of new boots for my Boxster it cost nearly a grand. These days I can do it for £500 and still get a decent tyre - if not top-of-the-line Michelins.
If you want to slide a car around then go to a drift day and get to enjoy it properly...
Answer: No. They can't have too much grip. Have you seen how crap at driving most people are? These tyres are saving their lives on a daily basis! OF COURSE extra grip is a good thing. Whilst it may spoil cornering fun for those with the inclination it also provides vastly superior braking performance. Coupled with ABS this probably saves more lives than all the other road safety innovations combined.
As to the cost of the rubber? Well, hell. If it saves your life isn't it worth it? And competition is now making these wider, lower profile tyres far cheaper than they were ten years ago. When I first bought a full set of new boots for my Boxster it cost nearly a grand. These days I can do it for £500 and still get a decent tyre - if not top-of-the-line Michelins.
If you want to slide a car around then go to a drift day and get to enjoy it properly...
Don said:
Answer: No. They can't have too much grip. Have you seen how crap at driving most people are? These tyres are saving their lives on a daily basis! OF COURSE extra grip is a good thing. Whilst it may spoil cornering fun for those with the inclination it also provides vastly superior braking performance. Coupled with ABS this probably saves more lives than all the other road safety innovations combined.
I disagree slightly. The incredibly high grip levels mean most people never experience anything near a minor slide, never mind a total loss. There are never any warning signs. Then, one day, when the grip they take for granted isn't there for whatever reason, they're doing a much higher speed than in a suitably tyred car and make a bigger dent in the scenary.It's a double whammy- they never feel they're near the limit so never introduce any level of 'handling sympathy' (in other words they're happy to make ham-fisted direction changes) and, when it all goes wrong, it does so big style.
Northern Munkee said:
I was told the whole front suspension tyre geometry combo was such that it could not be driven at slow speed without PAS.
Thats one of the benefits of PAS believe it or not, it allows the suspension geometry to be designed with what's best for grip and handling, rather than a compromise between what's best for grip and handling and whether the driver can actually move the steering wheel at low speed.Arguably it's a bad idea in case the PAS fails, but it's pretty rare, and most cars can be steered at speed without it.
10 Pence Short said:
It's a double whammy- they never feel they're near the limit so never introduce any level of 'handling sympathy' (in other words they're happy to make ham-fisted direction changes) and, when it all goes wrong, it does so big style.
And in case the tyres would give any feedback about imminent danger, the ESP system corrects any deviations from the supposed trajectory so the driver isd none the wiser... until they land in the scenery. Every day I see how close people are driving to near the outer edge of the envelope in blissful ignorance - especially in adverse weather conditions.
f1nn said:
There's no doubt that manufacturers are over tyring cars today, but it's just another step in our nanny culture.
If anything it's more to do with the fashion for mahoosive alloys with elastic band tyres imo?"19s are like so last season. If you ain't riding on 'dubz' then you ain't cool"...
...or something like that!
Don said:
OK. Are modern cars over-tyred. i.e. Do they have too much grip?
Answer: No. They can't have too much grip. Have you seen how crap at driving most people are? These tyres are saving their lives on a daily basis! OF COURSE extra grip is a good thing. Whilst it may spoil cornering fun for those with the inclination it also provides vastly superior braking performance. Coupled with ABS this probably saves more lives than all the other road safety innovations combined.
As to the cost of the rubber? Well, hell. If it saves your life isn't it worth it? And competition is now making these wider, lower profile tyres far cheaper than they were ten years ago. When I first bought a full set of new boots for my Boxster it cost nearly a grand. These days I can do it for £500 and still get a decent tyre - if not top-of-the-line Michelins.
If you want to slide a car around then go to a drift day and get to enjoy it properly...
Totally disagree. Wider rubber is a nightmare in icey conditons where it'll let go easily and without warning while the complete lack of feedback leads to poor driving and also an over reliance on the grip offered. As a result people no longer think about the way they approach a corner or whether they're leaning on the tyres to much. When it all goes wrong it's also generally at a higher speedAnswer: No. They can't have too much grip. Have you seen how crap at driving most people are? These tyres are saving their lives on a daily basis! OF COURSE extra grip is a good thing. Whilst it may spoil cornering fun for those with the inclination it also provides vastly superior braking performance. Coupled with ABS this probably saves more lives than all the other road safety innovations combined.
As to the cost of the rubber? Well, hell. If it saves your life isn't it worth it? And competition is now making these wider, lower profile tyres far cheaper than they were ten years ago. When I first bought a full set of new boots for my Boxster it cost nearly a grand. These days I can do it for £500 and still get a decent tyre - if not top-of-the-line Michelins.
If you want to slide a car around then go to a drift day and get to enjoy it properly...
my 245s on 3lr z4 were sliding around a lot this morning, italian tune up before it's MOT very slippery in the cold and damp spinning up in third in a straight line even with plenty of tread left. In the dry you would struggle to get wheel spin unless you were really trying though, probably a good safe compromise for most conditions on the road, though 165 section rears on a 1.8 sport mx5 was some of the most fun track time I've had.
very slippery in the cold and damp spinning up in third in a straight line even with plenty of tread left. In the dry you would struggle to get wheel spin unless you were really trying though, probably a good safe compromise for most conditions on the road, though 165 section rears on a 1.8 sport mx5 was some of the most fun track time I've had.
My last car (ITR) had 205/45/R16 and my current (Eunos) has 195/50/R15, and I think both were just about perfect for what they needed to be. They both still have plenty of grip when driven properly, but if you want to play you can.
I'd always go for the smallest possible wheels for the lightness and ability to give it some sideways action if the need took me.
OTOH, my old Clio 182 also had the same sized tyres as the teg, but on that car, it felt over-tyred - it was too grippy, and when it did let go, it went suddenly, and nearly caught me out once - and I wasnt even driving quickly at the time. I always felt the Clio would have been better on 195/50/R15 like the original 172.
I'd always go for the smallest possible wheels for the lightness and ability to give it some sideways action if the need took me.
OTOH, my old Clio 182 also had the same sized tyres as the teg, but on that car, it felt over-tyred - it was too grippy, and when it did let go, it went suddenly, and nearly caught me out once - and I wasnt even driving quickly at the time. I always felt the Clio would have been better on 195/50/R15 like the original 172.
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