[concours] Re: Tire Size on S1 XKE

I have a bit of a question with the whole sizing thing here…

If a 6.40H15 Dunlop is OK as an OEM (And IMHO I’d only put them on a
trailer queen) tire, I can’t understand why they use a 195-75R15 instead
of a, say, 185HR15.

The two sizes will have similar diameters, yet…

195-75-15 is an already obsolete size, for JCNA to go to THIS seems odd.
Also, there are no H or V rated tires made in that size, I should think
that the 185R15 should be used for a few reasons.

  1. Since it’s a size used as OEM by a great deal of classic cars, it’s
    gonne be available for a while. (XKE, TR6, Stag…etc…), From all I can
    find, I dont seem to be able to locate any cars that used a 195-75-15 as
    OEM, if anything I’d say that the 205-70VR15 would make more sense because
    it’s the size used by the XJ40s and will be around for some time yet.
    Coker has Michelin Redline X’s, Michelin XWX (VR blackwall) and Michelin
    XAS (HR Blackwall) tires in current production in this size. However,
    they’re expensive…

  2. At least tires in this size (XAS for example) will be available in the
    Original speed rating. The OEM Dunlops were H speed rated, no 195-75s
    are. Also, 185HR15s were OEM on, what was it, the S2? I thought it was
    one of the XKEs…

Just my 2pence…

Bill Weismann
billw@jag-lovers.org
Modern Pages Webmaster
91 VDP
66 XKE OTS 4.2 <–Been a member of our family for 48 hours. =)

Bill: Here are a couple of comments on your questions.

Bill Weismann wrote:

If a 6.40H15 Dunlop is OK as an OEM (And IMHO I’d only put them on a
trailer queen) tire, I can’t understand why they use a 195-75R15 instead
of a, say, 185HR15.

The owner, who originally filed to have the 195/75R15 tire size approved,
wanted wide white walls as were shown with many original Series 1 E-types, in
a radial tire. It was the only one he could find.

The two sizes will have similar diameters, yet…

According to Coker, the 640/15 overall diameter is 26.88" while the 185/70R15
diameter is only 25.20"; 1.68" less than the 640. The 195/75R15 diameter is
26.15", .73" less than the 640.

The 195 tread width is .16" wider than the 185 and its cross section is .60"
wider than the 185. These variances are smaller than those between the 185 and
the 640

195-75-15 is an already obsolete size, for JCNA to go to THIS seems odd.
Also, there are no H or V rated tires made in that size, I should think
that the 185R15 should be used for a few reasons.

  1. Since it’s a size used as OEM by a great deal of classic cars, it’s
    gonne be available for a while. (XKE, TR6, Stag…etc…), From all I can
    find, I dont seem to be able to locate any cars that used a 195-75-15 …
  2. At least tires in this size (XAS for example) will be available in the
    Original speed rating. The OEM Dunlops were H speed rated, no 195-75s
    are. Also, 185HR15s were OEM on, what was it, the S2? I thought it was
    one of the XKEs…

JCNA really hasn’t “gone” to the 195/75R15. The Rule Book now uses the
terms: “comparable or superior equipment”, “compatibility with the Jaguar” and
“consistent with the original profile”. With the lattitude allowed by that
wording, the Protest Committee ruled that the 195/75R15 met the general
physical size, compatibility and profile requirements. If the ONLY tires
considered authentic for Series 1 E-types, must have the numbers 640-15 (RS5)
or 185HR15 (SP41) etc. on their sidewalls, then the rules should say that.
Right now, they don’t.

Thanks for your thoughts, Dick Cavicke

Bill: Here are a couple of comments on your questions.

Bill Weismann wrote:

If a 6.40H15 Dunlop is OK as an OEM (And IMHO I’d only put them on a
trailer queen) tire, I can’t understand why they use a 195-75R15 instead
of a, say, 185HR15.

The owner, who originally filed to have the 195/75R15 tire size approved,
wanted wide white walls as were shown with many original Series 1 E-types, in
a radial tire. It was the only one he could find.

The two sizes will have similar diameters, yet…

According to Coker, the 640/15 overall diameter is 26.88" while the 185/70R15
diameter is only 25.20"; 1.68" less than the 640. The 195/75R15 diameter is
26.15", .73" less than the 640.

The 195 tread width is .16" wider than the 185 and its cross section is .60"
wider than the 185. These variances are smaller than those between the 185 and
the 640

195-75-15 is an already obsolete size, for JCNA to go to THIS seems odd.
Also, there are no H or V rated tires made in that size, I should think
that the 185R15 should be used for a few reasons.

  1. Since it’s a size used as OEM by a great deal of classic cars, it’s
    gonne be available for a while. (XKE, TR6, Stag…etc…), From all I can
    find, I dont seem to be able to locate any cars that used a 195-75-15 …
  2. At least tires in this size (XAS for example) will be available in the
    Original speed rating. The OEM Dunlops were H speed rated, no 195-75s
    are. Also, 185HR15s were OEM on, what was it, the S2? I thought it was
    one of the XKEs…

JCNA really hasn’t “gone” to the 195/75R15. The Rule Book now uses the
terms: “comparable or superior equipment”, “compatibility with the Jaguar” and
“consistent with the original profile”. With the lattitude allowed by that
wording, the Protest Committee ruled that the 195/75R15 met the general
physical size, compatibility and profile requirements. If the ONLY tires
considered authentic for Series 1 E-types, must have the numbers 640-15 (RS5)
or 185HR15 (SP41) etc. on their sidewalls, then the rules should say that.
Right now, they don’t.

Thanks for your thoughts, Dick Cavicke

Dick,

Sorry for the delay in replying. My mailer hid a bunch of mail.

When I mentioned 185HR/VR15 I meant a 185R15… this is actually a
185-82R15, when no aspect ratio is mentioned the ratio is assumed to be
82. These would be closest to the OEM 6.40XH15 size. 185-70s would, of
course, be a lot lower. A replacement for the 185R15 would be a 205-70-15
or thereabouts. Last time I checked the 185R15 had, if I recall, an
Overall Diameter of about 26.95inches. Also, this does vary quite a bit
from manufacturer to manufacturer.

BillOn Tue, 26 May 1998, Dick Cavicke wrote:

In a message dated 98-06-01 05:34:35 EDT, you write:

<< A replacement for the 185R15 would be a 205-70-15
or thereabouts. >>++++++++++++++++++++++++++++++++++++++++++++++
Bill: Will 205-70-15 tires on a series II pass muster at a concours?

Regards, John Walker
69 2+2

In a message dated 98-06-01 05:34:35 EDT, you write:

<< A replacement for the 185R15 would be a 205-70-15
or thereabouts. >>++++++++++++++++++++++++++++++++++++++++
Bill: I forgot to mention I show in D3, if that makes a difference

Regards, John Walker
69 2+2

In a message dated 98-06-01 05:34:35 EDT, you write:

<< A replacement for the 185R15 would be a 205-70-15
or thereabouts. >>
++++++++++++++++++++++++++++++++++++++++++++++
Bill: Will 205-70-15 tires on a series II pass muster at a concours?

Regards, John Walker
69 2+2

John,

From my experiences, the 185R15 is your best bet as far as judging goes…
as the 205-70-15 is NOT the OEM size, it will indeed cost you points.

As far as 185-15s go… You can still obtain the following tires:

Avon Radial (Not too bad… grips OK… lousy in the rain… but since few
E-Types get used in the rain it’s almost academic)

Michelin XVS or XAS: Coker sells these, I forget which one is about $10
higher…But that’s the slightly newer tread design. This same tire, now
only sold for the restoration market was still being put on new BMWs sold
in America as late as 1988 (528e… also was OEM on the old 733i and 633csi
before they went to those god-awful TRXs), Mercedes also used it up into
the mid 80s, so it’s not a terribly outdated tire. However! They stink
in the rain, but grip pretty well. These are also “H” speed rated.

Hope this helps!

BillOn Mon, 1 Jun 1998 J1J2WALKER@aol.com wrote: