"Modestly tyred"

[J4CKO]

Just reading the Autocar review of the Vauxhall Adam, what is basically a supermin and the review was saying that it handled ok despite having modest tyres, it had 195 width tyres, not sure what the wheel size was but a quick look suggests that 18 inch wheels are available. To me 195 section tyres still seem fairly wide, the Golf GTI originally wore 175/13's, then went to 185/14s and that had, in the case of the 16 valve, 139 bhp, this is a supermini rocking a 68 bhp engine, incidentally the same as our Citroen C1 which wears 155/14s which to me seem appropriate to the power output and size of car.

I am surprised at Autocar as they usually eschew the smaller wheel and tyre combos, how can a 68 hp supermini trouble the available grip of such huge wheels and tyres, the C1 never feels short of grip given the power avaialble, surely these massive wheels on low powered, small cars ruin the drive, putting 195 tyres on a C1 drops the mpg by about 10 so how much fuel and power is beign sapped by the current fashion for massive wheels ?

[iva cosworth]

I was surprised when my 2008 1.25 Fiesta came with 195/50 15 tyres.

This was the "ultra low profile" fitted to a car i also owned then,the 1983 RS 1600i.

Obviously 25 years makes a difference.

[v8will]

I can't see the width in isolation being a major problem, within reason of course. It's the larger diameters that kill MPG, performance and invariably ride quality due to much larger unsprung weight of big wheel/tyre combos.

[Mastodon2]

Why does a 68bhp car need 195 width three? Those are the same as my EP3!

[iva cosworth]

Mastodon2 said:

Why does a 68bhp car need 195 width three? Those are the same as my EP3!

That's what i thought re the Fiesta with 65bhp

[deadtom]

J4CKO said:

Just reading the Autocar review of the Vauxhall Adam, what is basically a supermin and the review was saying that it handled ok despite having modest tyres

are you sure it they were referring to the tyre size and not the quality of said tyres?

[xRIEx]

As a pure guess, grip required is not just about engine output - getting 1135Kg (plus occupants) turned and stopped (and the focus on safety) requires more grip. The Mk1 GTI was 810Kg according to wiki.

Having said that, it's probably not due to much more than image.

[Willy Nilly]

xRIEx said:

As a pure guess, grip required is not just about engine output - getting 1135Kg (plus occupants) turned and stopped (and the focus on safety) requires more grip. The Mk1 GTI was 810Kg according to wiki.

More weight = more grip.

[Krikkit]

The answer is simple - you've got to get the wheels looking decently sized for the huge wheel arches (i.e. so everyone can spec the 18" option without it looking like it's on bicycle tyres), and to make sure it feels as solid as possible. Remember: to the car buying public you can't have too much grip.

[J4CKO]

deadtom said:

J4CKO said:

Just reading the Autocar review of the Vauxhall Adam, what is basically a supermin and the review was saying that it handled ok despite having modest tyres

are you sure it they were referring to the tyre size and not the quality of said tyres?

Yes it was size, OEM tyres are rarely rubbish, mentioned it a couple of times.

[911stu]

A Vauxhall ADAM!!!! Have they really called a car Adam.

[Martin_Hx]

Mastodon2 said:

Why does a 68bhp car need 195 width three? Those are the same as my EP3!

205 45 standard, but mine wears 215 40's :-)

Edit - oh and modern day tyre size may be due to the weight not power of modern cars ?

[kambites]

911stu said:

A Vauxhall ADAM!!!! Have they really called a car Adam.

Same as the Ferrari Enzo, really. Named after Adam Opel. I suppose the fact that they badge is as a Vauxhall in the UK makes it a bit odd, though.

Oh, and 195 is ridiculous in a car of that power and weight. No wonder modern mainstream cars are so dull.

[Mr2Mike]

v8will said:

I can't see the width in isolation being a major problem, within reason of course. It's the larger diameters that kill MPG, performance and invariably ride quality due to much larger unsprung weight of big wheel/tyre combos.

Wider tyres increase rolling resistance. Try pedalling a mountain bike after being on a road bike with narrow tyres-the difference is very noticeable.

[Otispunkmeyer]

Read the review of the Adam vs 500 in this months TG mag and was quite amazed that they're gonna sell it with the option of 18 inch wheels. It's a supermini, how are the arches even big enough? The 500 has much smaller wheels and that looks fine. I can only imagine the ride on 18's in such a short car is going to be abhorrent.

[thiscocks]

kambites said:

Oh, and 195 is ridiculous in a car of that power and weight. No wonder modern mainstream cars are so dull.

For a car of that weight id say 195 is about right especially given the bigger wheels.

[dbdb]

Modern tyres seem vast to me, with even small cars fitted from new with tyres which twenty years ago would only have been fitted to a fairly exotic car. The Eighties BMW 525e came with 175 HR 14 wheels!!

[kambites]

thiscocks said:

kambites said:

Oh, and 195 is ridiculous in a car of that power and weight. No wonder modern mainstream cars are so dull.

For a car of that weight id say 195 is about right especially given the bigger wheels.

It only weighs about a tonne! I'd say 165s would be about right, probably on 15 inch wheels.

[veevee]

v8will said:

I can't see the width in isolation being a major problem, within reason of course. It's the larger diameters that kill MPG, performance and invariably ride quality due to much larger unsprung weight of big wheel/tyre combos.

Ride quality yes, MPG, probably not - larger diameter wheels, same effect as higher gearing?

kambites said:

thiscocks said:

kambites said:

Oh, and 195 is ridiculous in a car of that power and weight. No wonder modern mainstream cars are so dull.

For a car of that weight id say 195 is about right especially given the bigger wheels.

It only weighs about a tonne! I'd say 165s would be about right, probably on 15 inch wheels.

^^ exactly this.

[nixon1]

I just selected the £120 iPhone cradle option when building my Adam

But yer, umm, back to the tyres. According to the options list, you can choose from

185/65 R15
195/55 R16
215/45 R17

or...

225/35 R18


My S4 has the same size 18s, and it weighs 1.7 tonnes

Edited by nixon1 on Thursday 7th February 02:37