Removed

ok then recapping: Dash and Dorian believe that wider tyres = better grip IN THE DRY but that won't be the case in wet conditions, being wet or dry the only parameter difference. ok?

no as you disputed the fact that he actually did go to Japan and he actually did try the tyres. I am reporting what was said by him (hence being his word)

I only asked if he had credentials in order to assertain whether he was competent enough to make such a judgemment for Nissan (as the previous speaker claimed he had bee employed by Nissan for just such a purpose. Was I professing my opinion as a matter of consultancy to nissan? NOPE. Do I have any more credentials than than Mr Brewer? I cannot say until I know what credentials he has. Did I say I had more credentials than him? Nope Did I offer an opinion on an advisory basis about a tyre to a car manufacturer or to anyone else? Nope. Do I have a platform to profess these opinoins like Mr Brewer? Nope. Am I employed by Nissan or have I ever professed I have? Nope. So why should I take the word of someone Like Mr Brewer (or Mr Clarkson for that matter) just on the basis of someone having a familar face and a public forum to broadcast from? Also my reference to Europe was made under the basis that I seriously doubt that the boys in Nissan Omori even know who Mr Brewer is let alone value his input to hire him, (as the previous speaker claimed) well i was present at that conversation and Max only reported what mr Brewer said. I can confirm that. So I guess it's your word against his. IIRC he mentioned the fact that he went to try (alongside others apparently) different tyres back in Japan and did give feedback as to whether they could be deemed ok for the Uk climate. he also said his feedback had been negative. I'm not saying he wasn't talking bollox, I'm just reporting what was said

yup, very curious of unusual stuff on the Z

You explained to "him' that we are discussing grip in WET conditions? And not the dry? no, mine was a general question. is a wider tyre grippier than a narrower tyre. Appreciate the fact that you do agree with me in saying that (at least in the dry) wider tyres are grippier. I do still hold my reservations to the explanation you (well the website you mentioned) gives as to why a narrower tyre is grippier in the wet

Not in dry but it the wet it actually can be, hence why wet tyres on race cars can be narrower, ever seen snow tyres on a rally car, why do you think they are so thin? : To place the pressure on a narrower area to improve grip levels. In the wet yes, see above. We are saying that the contact patch DOES NOT change, irrespective of tyre width, nor does the surface area load placed on that contact patch. See Below. We never said "a wider tyre has less grip" we said that a wider tyre has an equal load on its contact patch and that the contact patch remains the same size. However the wider a tyre is in the wet the more prone it is to aquaplaning or slip angles. Fat or thin? The question of contact patches and grip. If there's one question guaranteed to promote argument and counter argument, it's this : do wide tyres give me better grip? Fat tyres look good. In fact they look stonkingly good. In the dry they are mercilessly full of grip. In the wet, you might want to make sure your insurance is paid up, especially if you're in a rear-wheel-drive car. Contrary to what you might think (and to what I used to think), bigger contact patch does not necessarily mean increased grip. Better yet, fatter tyres do not mean bigger contact patch. Confused? Check it out: Pressure=weight/area. That's about as simple a physics equation as you can get. For the general case of most car tyres travelling on a road, it works pretty well. Let me explain. Let's say you've got some regular tyres, as supplied with your car. They're inflated to 30psi and your car weighs 1500Kg. Roughly speaking, each tyre is taking about a quarter of your car's weight - in this case 375Kg. In metric, 30psi is about 2.11Kg/cm². By that formula, the area of your contact patch is going to be roughly 375 / 2.11 = 177.7cm² (weight divided by pressure) Let's say your standard tyres are 185/65R14 - a good middle-ground, factory-fit tyre. That means the tread width is 18.5cm side to side. So your contact patch with all these variables is going to be about 177.7cm² / 18.5, which is 9.8cm. Your contact patch is a rectangle 18.5cm across the width of the tyre by 9.8cm front-to-back where it sits 'flat' on the road. Still with me? Great. You've taken your car to the tyre dealer and with the help of my tyre calculator, figured out that you can get some swanky 225/50R15 tyres. You polish up the 15inch rims, get the tyres fitted and drive off. Let's look at the equation again. The weight of your car bearing down on the wheels hasn't changed. The PSI in the tyres is going to be about the same. If those two variables haven't changed, then your contact patch is still going to be the same : 177.7cm² However you now have wider tyres - the tread width is now 22.5cm instead of 18.5cm. The same contact patch but with wider tyres means a narrower contact area front-to-back. In this example, it becomes 177.7cm² / 22.5, which is 7.8cm. Imagine driving on to a glass road and looking up underneath your tyres. The narrower tyre has a longer, thinner contact patch. The fatter tyre has a shorter, wider contact patch, but the area is the same on both. And there is your 'eureka' moment. Overall, the area of your contact patch has remained more or less the same. But by putting wider tyres on, the shape of the contact patch has changed. Actually, the contact patch is really a squashed oval rather than a rectangle, but for the sake of simplicity on this site, I've illustrated it as a rectangle - it makes the concept a little easier to understand. So has the penny dropped? I'll assume it has. So now you understand that it makes no difference to the contact patch, this leads us on nicely to the sticky topic of grip. http://www.carbibles.com/tyre_bible.html Must have missed this post... so it appears that now we all agree that wider tyres have better grip. I appreciate the fact that this thread started as a discussion for wet conditions, and for that I hold my hand in sort of generalising it to "wider=better?" It'll be curious to hear what Miraglio has to say for wet conditions. I personally never stated that wider tyres have better grip than narrower tures in the wet

Dash do you still agree with the above statement you made? ar are we ONLY talking about wet conditions also on the above post? please clarify

Where is Mr. brewers credential relating to being a doctor in automotive compound adhesion (would that be physics?) Secondly was he employed by Nissan? Whilst I have no evidence to the contrary I find it hard to believe that a reporter could be employed as a competent consultant during the initial trials of a vehicle or even the following NTE Homolgation trials that took place in various countires throughout europe but were managed by both NTE Cranfield and NTE Bonn, where incidently the nurburgring testing team reside? But without evidence to the contrary I am open to admit that I may be wrong. Personally I would not take the wrok of an ex salesman come TV presenter as bonafida evidence upon which to make my choice of tyre manufacturer for the whole of europe on. sorry a bit late to comment on this, but just to add some more spice: first you say you are no scientist, now you want credentials...do you have any more credentials than mr Brewer? Also, the Stone's are on Zeds worldwide, not just Europe

PS will tidy up the thread to make it a bit more clutter free

so let's recap: in you 2 guys' opinions (let's use 2 widths for examples) a 245 tyre has more or less grip than a 275 tyre? same brand, compound, tread pattern PSi and condition of the road 2 tyres same brand different widths same conditons (WET)) the 275 will be more prone to aquaplaning (ergo less grip) than the 245. Predominetly due to the difference in the shape of the contact patch the spreading of the pressuere placed upon that tyre by its vehicles weight over a different shaped contact patch and the fact that the capilary action with in the thread of that tyre is not the same due to the reduced contact pressure at any singal point. ok hopefully Miraglio will be on board soon to discuss your position. Is your position the same for DRY conditions?

Dash so you disagree with Dorian then. in his post quoted above he said he went larger tyres to have more grip (to handle the extra power from the SC) but at the same time he says he never had any isues with narrower tyres NA surely Dorian above admits of wider tyres having more grip then?

keep asking ME?

so let's recap: in you 2 guys' opinions (let's use 2 widths for examples) a 245 tyre has more or less grip than a 275 tyre? same brand, compound, tread pattern PSi and condition of the road

I never said that Dorian, don't put words in my mouth. but if you don't mind I'd rather believe an engineer with a 500hp 300zx Wet conditions are a separate issue Dash. When I referred to Dorian's post and he "got cross" was since he discarded the fact that he went from a 245 width to a 275 width, as irrelevant

as I sd no point in trying to argue with me as I am not qualified enough, but guess what, I'm quite convinced he's more competent that you and Dash put together, again just a gut feeling the translating thing is simply due to the fact that when you interpret (as in are the interpreter of) or translate technical subjects, you need to have a good knowledge of technical terms for that specific subject. (which in this case I haven't got)

no point in trying to explain as I sd... will get him on board, and hopefully he'll explain to you 2 why you are wrong

I just tried to translate it from his post... he'll explain you better surely...

PS I'll get the engineer guy to come over, he does speak english... I'm sure he'll be happy to answer all your queries, as will be all the F1 teams engineers

Dash you'll have to contact all F1 team then and suggest them according to your science knowledge they should all go with bicycle tyres as they will give you more grip

nope as the above was said by Dorian and it is not correct. wider is better for grip full stop. the fact that in the wet there's other variables to take into consideration is another matter

just acknowledge you 2 were wrong in not even considering that a tyre is a deformable object and act graciously for once will you

didn't know you actually went through THREE Zeds then ! lmao it must have been a very embarassing moment indeed

tell him: go into your techincal system, pull out the TSB's and voila' 2 fixes to be had

I know but it's fair to say there a few decent dealers scattered around the country, just need to find one

LMAO! it all makes sense now! bird's custard, bananas, hairy arm........ custard car! anyway back to story...