14.1 - Wheels and Tires for Saloons ( Chris Burdo,  June 22, 2005 )

Tire information for Saloons

One of the more popular questions that appear on the Saloons list is in regards to tires.
I’ve put together the following information as an informational guide in regards to the proper tire sizes for each model.

General Information

From Greg Bernier regarding the safety issue of mixing of radials and cross-ply tires:

You absolutely cannot mix radials and crossplies, in any way. I know from
experience. I unwittingly put radials on the front of a 1974 Mercury Comet I
once owned (it had crossplies on the rear). At speeds over 45 mph the car
would wander and even swerve. It was totally unsafe on the highway. Knowing
no better, I thought something had happened to the front suspension, and did
work on that. No improvement. Finally somebody clued me in: "You NEVER mix
radials and crossplies".


From: Eric Hutchinson, Wed, 26 May 2004 regarding wheel sizes:

“the JCNA Rule Book in Appendix B lists 4 1/2x15 for the MKI, 5x15 for the MK2 and 5 1/2x15 for the 420.
Each with 6.40x15 Roadspeed for rubber. The MK2 and 420 also show the 185HR15 for later models.
There are 5 1/2 inch rims listed as standard for 240, 340, 3.4s and 3.8s also.


MKVII-IX – Tire size 6.50 x 16 as supplied from new.

From Tom Brady:

I am presently running tubeless radial wide white radial tires (215/70R16) obtained from Diamond Back Classics
in South Carolina. I have a set on my 59 and 61 MK IXs. The 215/70R16 closely matched the diameter
and width of the 6.70/16 tire but has a better contact patch on the road since it is a radial.
Handling is like a modern car with radial tires.

From Greg Bernier:

Why not use 6.50-16? There are lots of brands to choose from. According to the original Mark IX Owners' Manual,
it lists the correct tire size as 6.50/6.70-16. It works fine in JCNA judging. I use "Lester" tires.
Universal Tire and Lucas Tire both carry them.

I have been running Lester 6.50X16 bias-ply tires on my Mark IX for
15,000+ miles. I have driven long highway distances at speeds of 70-75
m.p.h., and, aside from having the normal characteristics associated with
bias ply tires, they have been very satisfactory. I have run in JCNA slalom events
with times in the low to mid 50 second range, and the tires have been fine.
If I decide to put whitewalls on my DHC, I will go with the 6.00X16 Lesters.
Just reporting my own experiences with a brand of "vintage" tires currently being sold. (No affiliation with any tire mfrs. or sales companies.)

From: Dave

I just went into the garage and measured the height on my 1960 Mk IX.
It sits on 6.50 x 16 straight ply tires ( as originally specified)
The height from the ground to the underside of the frame by the drivers door is 8.5"
If I measure from the ground to the underside of the front cross member it is 10.5"

MK1 - Tire size 6.40 x 15 as supplied from new.

From: Eric Hutchinson, Wed, 26 May 2004:

I have a question on this subject. I'm looking to replace the tires on
my 59 MKI. Lots of options and I'm curious what others have used. I'm
looking for something in a 185x15 that will also fit in the spare wheel
well. My MKI is original/unrestored and I don't want something that
looks too aggressive if possible. Something with the look close to the
Roadspeed would be preferred. Would I be foolish to consider a bias ply
6.40x15 if I found one?


MK2, 340, 240 – Tire size 6.40 x 15 as supplied from new.

From Jack Verschuur:

It is my understanding that 205/70 on wire wheels cannot be fitted with the standard spats, you'd need to get the 'sports' spats, modeled on the Coombs rear arches, sort of. 195/70 has a smaller rolling circumference than the standard tyre.
Since you're in Holland, Vredestein make a perfect radial tyre for the Mk2, which can also be fitted with the standard spats.

From GNB

I am running Dunlop Narrow white wall tyres which are 205 X 75 X 15

From Mike Eck:

I have 205/70R15s on my MK2 and they don't rub the spats but on hard cornering or bumps they seem to
rub the front fenders using the original wire wheels.

From Gregory Andrachuk, June 7th, 2005

I recently bought a set of tires for my Mark 2:  15HR15
Universal Sport tires from Universal Tire; they have a 5/8 inch white band
and the tread pattern is identical to the Dunlop Sport tires; price for
5 tires: $895. Beautiful tires; I have not fitted the yet.

From Paul Saltwick, August 5, 2005

There should be many posts on this in the archives.  XJ-6 wheels
are the same bolt pattern as MK2 wheels, but the backspacing is
different, and changed again with the XJ-40.  The MK2,S,420
steel wheels are 15X5,4 inch backspacing, with a 5 X 4.75 bolt pattern
(same as GM). XJ-6 steel wheels are 15X6 with 5 inch backspacing.
The additional backspacing moves the inner edge of the wheel in
And helps with fitting a wider tire in the rear, but fouls the ball
joint, tie rod, wishbone in the front.  You need to use a 1/2''
spacer and longer studs to fit XJ-6 wheels to the front.

Sterling Forsythe wrote on August 6,2005

I am running the Series 2, XJ6 wheels on my 1967 MK2
with Goodyear Wrangler 195-75R-15...... or at times the
Uniroyal Tigerpaw 195-75R-15 which tyre may now be out
of stock.  No problems getting the Goodyear at the moment
though.

I've fitted the longer threaded studs on the front hubs and
also use washers to clear the ball joint, tie rod, wishbone
in the front to prevent rubbing.  Some further refinements
were necessary at first to preserve the full turn steering
radius movement.  I have had this setup since 1997 as
a daily driver.


MKX/420G - Tire size 205 x 14 as supplied from new.

From Viejo:

The 420G I am buying has 215-14 tires on it now. The specs list 205-14 tires.

From Rick Cusack:

I'm a little late on this, but I replaced the 14" wheels on my 420G with 15"
wheels from a Series II XJ6. They look great, handle beautifully, and are
much more in keeping with the profile of the car.





420/S-Type – Tire size 185 x 15 as supplied from new.

From Clark:

I am running 205/75-15s on both my 1967 S-Type as well as my 1967 420.
As a matter of fact, I ran a 215/75-15 on the rear of the S-Type that came
off my 1988 XJ40 when the tyre went flat on the S-Type. So I know for a
fact they will fit the 420 and the S-Type. Both these cars have permanent
"spats" I will admit the 215s were a bit close and had to be persuaded to
go on.
THIS may be the difference, however. None of my cars run wire wheels.
I do not believe that you can get a 205 over the splined hub for a wire
wheel on any of these cars -- although I may be wrong.
In terms of clearance on the running, I have plenty of clearance on both
the front and rear of the car -- even under heavy load.

    I run either Continental or Bridgestones on all my vehicles.
This includes my Jags.  When I first got my 1988 XJ40 it was running
speed rated Pirelli P-4000s.  It took me about 2 weeks to decide I would
never buy a Pirelli tyre again.  They wear terribly and if the car sits for
more than 3-4 days you get a flat spot that takes a LONG time to drive
out.   If in fact you DO buy the Pirelli's you MUST make sure they are all
manufactured from the same plant. They will have the plant of origin molded
right in the side of the tyre.  On the tyres I run, I make sure they are
rated at least 400AA (360AB is acceptable as well) for wear and heat.

As for size. I have the steel wheels as well on both the 420 and
the S-Type. Both cars are running 205-75/15. These tyres will all fit the
rims with no problem. I have found the wider stance has made for better
handling and ride. I have a little over 10,000 miles on the 420 tyres and I
am really pleased with them. Anything wider and you will have a terrible
time getting the tyre past the "spat".  As it is, I carry a 2 x 12 and a
scissors jack in order to lift the car high enough to bring the tyre down on a
vertical plane to clear the hub in the rear.  The front will very rarely rub
when I make a right hand turn into my inclined driveway at too rapid a speed.
It is the only time I have heard it.

If you have wires -- this is probably the problem

From Jack Verschuur:

Just as an aside, I had 205/70 Dunlops on my 420 on steel wheels, which
worked a treat. Yes, the rears were a pain to change. No problems at the
front with the standard wheels, but with XJ6 wheels it didn't work without
spacers.

From Paul Saltwick

You have to consider the backspacing of the wheel (distance from
rear edge to hub face) when increasing the width. You can fit
wider wheels to the rear of an S/420, but they need to have more
backspacing, and you may have to remove the bumpstops. For
example, the stock 5X15 inch bolt on wheel has 4 inches of
backspacing and the stock Jaguar 6X15 wheel has 5 inches of
backspacing. This moves the wheel closer to the center and the
outside edge of the wider tire winds up in about the same place.
It is very much a trial and error fit with the S/420 and some 205
tires have wider sidewalls than others. The stock Jaguar S/420
wheels are 5 inch wide wheels, anyone that tells you otherwise
doesn't know how to measure wheels. If you can fit 205/70's on your
car with stock wheels, that is about the limit. Unfortunately, if
you look at the tire MFG's specs, most speed rated radials (above
SR -112 mph), including Michelin, are only approved for 5.5 inch
and wider wheels. The Pirelli P4000 is one exception, and that is
why it is popular with E Type owners with 5 inch wheels. Most of
the high performance rubber in 205/70 and 205/65-15 is rated for
5.5'' and wider wheels.


From Paul Saltwick:

Most of the available 185-15 tires are made for taxis or very
expensive. If you are keeping the stock 5 inch wheels, Pirelli
P4000 in 205/70-15 are the best value/performance, if you can fit
them in the rear without rubbing. I couldn't and went to 205/65-
15's on 6 inch wheels, which transformed the car more than all the
poly in baloneyland.

From John Quilter, June 7th, 2005

The Michelin 185X15 red stripe tire is still available as this
was the standard fitment on the TR6.  They are pretty pricey now
though and may be reproductions of the original.  I believe the aspect
was 80 although you should not notice any real difference to use 75.
I found some Bridgestone 195X15 75 and these were a good fit with
out rubbing on the front fender lips on my 1965 S TYPE with disc
wheels. They were reasonably priced at about $75 about 5 years
ago.  They don't however have as good a wear rating as the
Michelins.

From Iain Buxton, June 7th,2005

Special tires are always available from Diamondback. They
are on the web and they will go out of their way to
accomodate you.
Your original ratio was 185/75R15 as I recall giving a tire
size diameter of about 25.9 inches.  Go to
http://www.powerdog.com/tiresize.cgi to calculate this for
different tires.  Match this overall diameter so you do not
alter the gear ratios relative to tires and to keep speedo
accurate.  Width (185) is limited to an absolute max of 205
on the 'S' due to clearance on the rear fender but I would
not go more than 195 or you will get rubbing on the fender.
The wider the tire on the stock wheels the more you will
limit the turning radius in the front somewhat.
Tire Rack has the Goodyear Eagles with that period whitewall!

14.1.1 - Adding Coombs Arches to a 420/S-Type ( Iain Buxton,  May 26, 2005 )

Modifying the S-type/420 rear wheel arch,(Coombs style)

From Iain in Reno: (In regards to installing Coombs wheel arches in the S-type/420)

Well it seems to me that the Rear Wheel Reveal is in order
here! I have some pictures on the photo gallery showing the
result. It is interesting that the original 5 inch wire
wheel with a 195 tire looks totally lost in that rear space
when the Coombs Spats are welded in on the S-Type!
I have new 16 inch by 6 inch wheels and 225/60R16 tires and
that gives the same overall tire diameter as original.