Conference terri::cars_uk

    
    What were they?
    
    Mark

    HR is up to 131 mph, VR up to 150 ish, and ZR for more than that, but I
    dont know how much more.  SR is (I believe) about 110 mph.
    
    Micheldever Tyres, who I trust about such things, advised me to fit
    tyres of a rating that caters for the theoretical top speed of the car,
    even if you never intend to do that speed.  Thus, my old Pug had VR
    tyres, even though its top speed was right on the borderline between HR
    and VR ratings.
    
    I think I've just made it as clear as mud.
    
    John

    
    Thanks John,
    
    BTW, years ago I was recommended exactly the same thing about tyres.
    The argument being that the acceleration, braking and cornering forces
    were likely to be higher on a car with a high top speed and that tyres
    rated for a lower maximum would not be designed to deal with these,
    even if they were fine for any speeds you reached (How many people 
    drive at over 110 mph?).
    
    Mark

    Wrong !
    
    HR are good for continuous use at 118mph
    VR are good for continuous use at 130mph
    ZR are good for continuous use at 150mph
    
    
    The thing to watch though, is that you (usually) sacrifice some grip
    for the extra speed rating, unless you are on very expensive rubber.
    
    For example, the Snail used to like P7's, but didn't like the 130mph
    limit. Switching to P700's allowed a 150mph cruising limit, but caused
    all sorts of skidding around esp. in the wet.
    P-Zeros solved the problem - Z-rated 150mph cruising with all the grip
    she needed. But no change out of �1,000 for a set of tyres (every 10k
    miles).
    
    Similarly, I found that switching from V-rated Michelin radial bike
    tyres to Z-rated tyres caused a quite dangerous lack of traction in the
    wet. I am now back to running V-rated sport compound Metzelers, but now
    I find myself with autobahns to play with I am getting a little
    frustrated. ;-)
    
    So, I think that the law requires you to have tyres that match your
    vehicles performance, but any tyre is going to be good over its rated
    speed for short periods, so you only need the really high ratings if
    you want to get from Ferney to Calais in under 4� hours :-)
    
    Am�d�n

    I have been told that I am wrong.
    I don't think I am, but would welcome being put straight.
    Mr Kennedy doesn't have the guts to put his money where his mouth is 
    and reply in public though  ;-)
    
    Am�d�n

    I dont think there is a conflict between .4 and .6, since one is
    talking about maximum speed ever liklely to be used, and the other is
    talking about sustained , or "regular" maximum speed.
    
    John

    John,
    	Yes, that's what I thought might of happened, but Mr Kennedy (who
    still hasn't had the bottle to speak in public) wouldn't hear of it.
    
    Am�d�n

    
    Well seeing as Rob is upset about his bike being knocked over and wants
    to give as many people as much verbal as he can I will reply that I am
    looking for the notes which have gone over this subject more than once.
    
    As I remember HR is continuous to 130 mph, VR 130+ and ZR are for the
    new monsters capable of sustained 150+ (ie 190-200).
    
    The 118 mph quoted for HR sounds like the 'T' continental rating (ie
    Pirelli winter 190) and the 130mph (actually 131.25 or 210 kph) new
    rating for winter tyres.
    
    Now if I get some time, I'll take a look ......

    Hooray, a discussion  :-)
    
    Well Colin, how come my Pirelli Winter 190's are HR rated and the
    Winter 210's are VR rated then ?
    
    And the Pirelli book quoted continuous use at 150mph for the P-Zeros ?
    
    Am�d�n
    
    (Aren't you going to tell them how much I know about tyres then ?)

    Are you agreeing with what I said in .4 ??  I like being agreed with!
    
    I thought I was wrong about something once, but it turned out that I
    wasnt  ;-)
    
    
    John

    Well,
    	It is better that we agree than for one of us to be wrong :-)
    
    I have always thought of them a continuous ratings, Mr Kennedy's
    problem is that he thinks that the numbers that you quoted are the
    continuous ratings...
    Except that he and i agree that S rated is 113mph continuous.
    
    Anyway, I find it a bit tiring to keep up a steady 150mph for more than
    a few hours at a time.
    
    Am�d�n

The E-type recommended tyres (and fitted to mine) were Dunlop ER70VR15.  They
stuck like glue in the dry, and had amazing wheelspin problems under hard
acceleration in the wet ;^)  Cruising at 130-140 mph, they felt *good*  Mind
you, they were *extremely* fat and put a LOT of rubber on the road.

Brian
(Now running Sears 50,000 mile guarantee SR rated on the Alfa!)