I bought a 2005/6 XJ Super V8 a couple of months ago. It has 255/35/20 tyres all round on Sepang alloys.

I noticed that the rear tyre walls are much more of an angle when compared to the front, something I didn’t think much of until I decided to look into what maximum tyre size I could stick on the back.

Researching the forums suggests that the X350 should have 9" all round, is this correct, what do other X350 owners with 20" alloys have? Using a tape measure I can definitely say that the back wheels are wider. They actually seem to be about 9.5" on the front, 10.5" on the back.

There are no signs of any shim installation as far as I can see, having replaced the rear brake rotors I didn’t notice anything unusual. One of the rear tyres has a slight rubbing mark on the outside. Clearance on the inside looks fairly tight but with no sign of any tyre rub what so ever.

So, the rears have 255's on the back at the moment, is it worth trying a wider tyre? I was going to by some cheap part worn tyres first just in case the experiment fails!

I'd be interested to find out if anyone else has a similar wheel setup

 

Wheels are staggered but should be 9's all round, you can fit 9.5's with 275 on the back. the correct tires are 255 all round. 10's def don't fit only the XKR had 10's

 

Welcome to the forum! One of the mods will probably be along shortly to greet you, in the meantime why not stop by the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

The Sepangs for the X350 are all 9Jx20, there are also Sepangs for the X100 XKR which are 9Jx20 at the front & 10Jx20 at the rear. However these wheels are not interchangeable since the X350 has a PCD of 108x5 & the X100 has 112x5.

I did look into making up a 10" Sepang using the outer rim from the XK on an XJ hub, but this is quite a job, i would be interested to know if someone else had already done that.

Do you have the same brand & model of tyre on both axles? Because I noticed that the Falken FK452's on my XJR have a smaller contact patch with the road than Pirelli's that I saw on another car. If you have different tyres front/rear then that could be one reason why they look different.

The standard Sepang only has ~20mm clearance on the inside, have a look here https://www.jaguarforums.com/forum/x...ack-xjr-77305/

 

Not sure what you mean by "wheels are staggered" because they are all the same width & offset from the factory, with the same size rubber at each corner. Sepangs being 9Jx20 ET49.

10" is possible, it's just that there is no factory rim from Jag in 10" that fits.

The 21" Arden rims I have are 10" rears, 9" fronts.

 

The back end has a slightly wider track than the front. Does not really notice with standard 9's that's why my future plans will be XK wheels with 9.5 rears and 9 fronts.

 

I think I misunderstood the term staggered, I assumed it meant a difference between the wheel widths front and back. Does it refer to the spacing between the rims?

Maybe they arent the factory spec rims, they appear to be in one piece as well, they look different to all other Jag sepangs I've seen.

I've attached a picture of the front wheel. The rear looks identical apart from the wheel nuts are recessed about an inch deeper

 

That's not a Sepang!

 

Can't you slide a tape measure through the spokes for a quick check?

Good advice from Cambo above about visiting the new members section New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

Intro made! I got over excited after finding out the wheels are wider on the back and wanted to find out if this was normal and overlooked the new member info.

Hi Cambo, i guess the wheel design looks similiar so I assummed thats what they were, or some sort of varient. Mine seem to have more spokes than a sepang (and a real pain to clean!). Something I didnt notice until now.

I have run a tape measure and its about 9.5" at the front and 10.5" at the back. This is measuring between the widest parts of the rim, I'll get some more accurate figures tomorrow. I may try to put some wider tyres on the back in the next month or two and I'll post the results.

 

Be careful about wider tyres ! Others have tried it and found the tyre impacts the wheel arch liner and sometimes elsewhere. The XJR size and width should be your guide.

Of course if you are making body changes as well, then ignore this advice

 

OK I'll ask. What the hell is a sepang?

 

I am currently running 20x9 245/35/20 front, 20x10.5 275/30/20 rear with no issues on a 2004 XJR.

 

2004 XJR staggered X350