I think what is very interesting, is to see what tyres Jaguar themselves have chosen to fit on their series 1 E type in the newest issue of Octane
https://scontent-lht6-1.xx.fbcdn.net/v/t1.0-9/18118608_1432655980134441_3663107546642511876_n.jpg?oh=c93446842dd4bb70c96f77056690aa74&oe=59C2D08A
As another interesting point, would it be correct to say that currently the 185VR15 Pirelli Cinturato is the only period tyre made suitable to a E-type series 1?
So the concourse argument that the XK gang are very keen on would suggest that the Cinturato was the tyre of choice for the series 1.
i still also believe it is the best drivers tyre too. which is which is why i have it on my Lotus. But that is a no expense spared car and i also have Borraniâs on it.
Itâs no way the same Cinturato that was available back in the day. In the '60s the Cinturato was a fabric belt tire; only Michelin was steel belted. Today the Cinturato is steel belted. Quite different.
Jerry
I was wondering when tyres would start being mentioned - in the context of the factory restored 3.8 FHC as pictured/featured in Octane Magazine.
The first GLARING major non-originality aspect is being fitted with Pirelli Cinturato tyres - indeed any radial ply tyres.
E-types were NOT supplied ex-factory with Radial Ply tyres until the 4.2 E-type, and then from October 1965 onwards for UK and European market cars. E-types exported to USA, Canada and Australia did not get radial ply tyres until October 1967.
So no way should any claimed original 3.8 E-type have Pirelli Cinturatos on, albeit Jaguar freely offers they are happy to enhance their builds as requested by owners-to-be, albeit this Octane article suggests this grey FHC is to ORIGINAL specification. Better not enter any Concours events that judge originality.
There were legal reasons why USA, Canada, Australia and New Zealand didnât adopt radials until 1967, as the DUNLOP SP41 185-15HR radial as fitted to UK/European cars from Oct 1965, did not comply with regulations, and not until the improved DUNLOP SP SPORT 185-15VR tyre was introduced, that legal requirements were satisfied.
But thatâs back then, most premium brand radial tyres made these days of correct 185-15 dimensions are fully legal, as would be a modern version Pirelli Cinturato.
Roger
Roger- simply out of curiosity is there any record as to when in October '67 they started fitting the radials to USA/Canada/Australia cars? I can find no reference to tires in the IPL, so no help there. I ask because the build date of my car was October 5th, 1967 
Originality debate aside the Dunlop RS 185 tyre is no longer in production and there is no confirmed date when production will restart. So NLA in all markets because Dunlop closed the production line in Birmingham and moved it to India. Unfortunately the skills were not transferred which means until they reacquire them the Indian workforce are pretty much in the dark.
David
Doug,
Dates are approximate, but Chassis Numbers as quoted from Jaguar factory records are exact, albeit the Jaguar Heritage Trust book FACTORY ORIGINAL JAGUAR E-TYPE has provided monthly accurate dates of these particular Chassis Numbers from the factory production records.
Spare Parts Bulletin H.11 advises us that ALL 4.2 E Type and 2+2 models are now fitted with DUNLOP âSP SPORT 185VR15â tyres from Chassis Numbers:-
4.2 Open : 1E1920 onwards (RHD) and 1E16099 onwards (LHD).
4.2 Fixed Head : 1E21669 onwards (RHD) and 1E34847 onwards (LHD).
4.2 2+2 : 1E51059 onwards (RHD) and 1E77705 onwards (LHD).
The Bulletin also advises that the previous RS.5 (Cross-Ply) and SP.41 (Radial) tyres are no longer fitted as original equipment.
Now getting back to dates, and a common error made by many researchers and indeed publications, the actual Bulletin dates are the Date the Bulletin was issued, and not the date of effect of the Bulletins contents, in this case SPB H.11 is dated July 1968. But the Jaguar Heritage Trust book tells us that the six chassis numbers quoted all have a monthly accuracy date of effect of October 1967. Chances are these six quoted Chassis Numbers may not all be the same exact day, but may be a few days difference.
So dates themselves are not the prime indicator - the Chassis Number is EXACT.
So those are the facts - what anyone cares to do is their decision.
Certainly in Australia Concours, our RULES say the brand of a tyre doesnât matter, but the tyres fitted MUST be of their ORIGINAL construction type (ie, radial or cross-ply) and must be of the original size and speed-rating. So if a Radial Tyre it must be a 185VR15 and anything low profile or wider (such as 185/70 or 225) will be penalised, but it can be any brand you like - Michelin, Pirelli, Bridgestone or indeed Dunlop, but it doesnât need to be a DUNLOP SP Sport. Similarly with earlier Cross Ply tyres - Doesnât have to be a DUNLOP RS5, but regardless of brand must be 6.40 x 15" size.
This is a fairly sensible rule as the laws that apply to tyre manufacturing today, would not allow an exact replica of a 1967 tyre to be legally used, but the modern period reproduction tyres on offer comply to all current legal requirements, so are both legal and satisfy Concours authenticity requirements.
who makes a current 6.40 x 15?
Roger, in the US (JCNA, again), they report that Jaguar Service Bulletin M.23 (7-68) recommended only Dunlop SP41VR as a replacement tire for ALL E-types and so 185R15 radials are considered authentic for all Series 1 E-Types. Dunlop SP41VRs were down rated to an H rating to meet a change in the tire rating standards, so radials in 185R15 speed rated H or better are considered authentic â in the US.
This is in the JCNA Series 1 E-Type Judgeâs Guide, p. 15.
Jerry
Thanks for that information Roger! I guess that my car was one of the last cars to come with the bias-ply tires- in fact the change occurred 39 cars after mine, likely within a day or two (missed it by THAT much- sorry about that chief!)! Is there a source for all the spare parts bulletins? I have the interim parts lists, but I do not have all the bulletins.
Doug,
At one time the JDHT sold CDâs of the spares and service bulletins. The very 1st ones that I have came from a local Jaguar dealer that closed, others were copies of some of George Campâs and finally a CD from JDHT completed my sets.
Bob
889076
Plymouth, Mi.
With tyres, you need to be pragmatic. They are a consumable, they are a major aspect of vehicle safety, and the are these days LAWS in all countries that regulate allowable tyres to be fitted, if not necessarily back in the 1960s let alone 1950s (for XKs).
I have dug out my recently purchased JCNA Series 1 E-Type Judges Guide, and its page 16 now (not p.15), a section on TIRES (I do hate that spelling 
), and I have to say, a quick read I donât necessarily agree with the detail provided, HOWEVER the conclusions reached, and thus JCNA Concours Rules are not dissimilar to our local ACJC Concours Rules.
As before, we stipulate a radial tyre fitted must be 185x15 (and no low-profile), and if a cross-ply fitted it must be 6.40x15.
We donât stipulate a speed-rating, albeit in Australia that is a legal/roadworthy requirement, albeit these days an H rating is acceptable given our maximum speed limits. But no we do not allow a 3.8 E-type to have radial tyres fitted (most Judges know that), nor indeed 4.2 E-types built prior to the first factory original equipment introduction of radial tyres in Oct 1965 (if the Judge is up-to-speed) pre published Chassis Numbers (1E1409/ 1E11715/ 1E20978/ 1E32009), but we tend not insist on Australian (or USA) new cars not being allowed radial tyres until October 1967 (as per published Chassis Numbers). So we are a bit tougher it seems than JCNA.
One question though.
An E-type originally fitted with Cross Ply Tyres (RS5) was originally fitted with a Speedometer so calibrated.
When an E-type was factory fitted with Radial Tyres, that affected the speedo calibration, and a new Speedo was fitted.
My June 1966 OTS was UK delivered new, with a 3.07:1 rear axle, and Radial-ply 185x15 tyres fitted, thus has a C.26317 speedo fitted, quickly identified by the SN.6322/41 Smiths part-number printed on the dial.
If my car was built 12 months earlier it would have had Dunlop RS5 fitted, thus would have had an SN.6322/33 speedo fitted. So something to watch out for. Does JCNA check that for any speedo/tyres-fitted mismatch - I suspect not, and cant quickly see any mention in the Judges Guide.
But back to Dougâs Oct 1967 E-Type - what speedo SN.6322/?? do you have fitted?
That will tell you whether it was fitted with RS5 or SP Sport radials when new - donât know your rear axle ratio, as that affects speedo calibration as well, the /41 and /33 above are when with a 3.07:1 axle, standard for UK (and Australia).
Roger
Hi Roger,
I would appreciate knowing what part of the tyre detail, that spelling is just for you, you do not agree with. This guide has been a work in progress for the past14 years and weâre always open to any new documented additions.
Bob
889076
Plymouth, Mi.
Roger- My speedometer is marked âS/N 6332/00 1312â. The IPL I have doesnât list the /00 part number. The Series I 4.2 parts list has a 6332/00A listed for a 3:31 final drive and 6.40x15" RS.5 tyres, but my car is a 3.54 final drive car (typical for USA). The 1968 IPL lists the /03 speedometer for the 3.54/miles unit. I wonder if this was a replacement unit sometime in its past? More mysteries. Not that it matters, but Iâve converted my final drive to 3.07/1 and have had the speedometer recalibrated for that ratio.
fwiw
69roadster- thanks for posting that! However the only /00 on that list is for a 3.8 with 1216 rotations per mile (3.31/1 ratio). I have enclosed a photo of my speedo and it is clearly /00 and 1312.
The mystery deepens (not a big deal, just a curiosity to me).
Gâday Bob,
My comment about American spelling of TIRE, rather than English spelling TYRE was just a joke - sorry about that!
But if you want my comments about the section on TIRES on page 16 of the JCNA Series 1 Judges Guide - I will send them to you direct later today when I get a bit more time. This is not the forum. I only mentioned the JCNA judges guide in response to the previous posting that raised that guide as a reference.
Roger
Sorry Doug,
I can do no better than offered by 69roadster, indeed a better listing than I have ready at hand.
It is a shame Jaguar stopped updating their publication J27, a multi-paged booklet âDATA FOR ORDERING SPEEDOMETERSâ that was totally comprehensive of ALL speedometers in use as at date of publishing - I have the original issue of April 1959, the first revision of March 1960, and the second revision of January 1963 so starting to list 3.8 E-type Speedos, but I am not aware of any later revisions/updates.
Will have a look through some 1960s references I have, but not optimistic - as you say, a bit of a mystery.
Roger
Hi Roger,
I find it strange that some of my posts show up here and just about the same number go only to the topic. Please do send your thoughts.
Bob
889076
Plymouth, Mi.
