Pretty much as the title says, what do you think boys?

First question might be "why would you want to do that?" well i'm of the opinion that the XJR is terribly under-tyred.

The actual contact width of my 255/35/20 Falken FK452's is only 210mm at best



Yep, so much for 255's...

Now, why 295's? Well as is turns out a 295/30/20 is as close as dammit to the circumference of the standard 255/35/20.

You can see for yourself here Tire size calculator

295/30 is a difference of only -0.2%, a 285/30 is -1.1% which is a bit too much I think...i'm not sure if the computer wizardry would handle such a difference in speeds between the front & rear axle (you know, ABS, DSC, etc all rely on comparing measurements between wheel speeds).

So that's it, it'll have to be a 295/30. But will it fit, in theory that's 40mm wider than stock?
I crawled under the car & made some measurements...



Here's a good example of how a 255 really only has a contact width of 210, but this works in favour of squeezing the 295 under the wheel arch.



With the rear suspension fully deflated this is the measurement from the outer edge of the tyre, just above the lip of the rim, to the inside of the wheel arch, as you can see there is about 25mm of room to play on the outside. Fully deflated the ride height was 323mm, compared to my new ride height of ~360mm, which becomes ~345mm above 100mph...what that means is there is really more than 25mm, it's just that 25mm is the "worst case"



On the inside it's a different story, you can see here that the issue is the clearance between the inside of the wheel arch & the rim itself.



There is about 22mm of clearance from the stock 9" rim to the plastic lining of the wheel arch.



So that's really, really tight when we want to add 40mm of tyre, but will be doable.

The issue now is to sort out rims, I need a 10" with the right offset. Have an idea but it'll be expensive if it doesn't work....
Not too keen on using wheel spacers, but it might also be necessary, maybe a 10mm spacer on the rear...
The other option is to trim away the plastic lining of the wheel arch on the inside, but that all depends on what's behind, the lining is there for a reason....

Pity Falken don't do this size, i'll be looking at Dunlop Sport Maxx GT...the price is...ouch..

I tried 275 and they rubbed against the inside wheel liner.

I've just from a guy in the UK who's running 285's on the back of his X358 without issue, trying to get more details from him now.

jahummer, was that on the Aruga rims? What profile did you have on the 275's? What brand tyre?

Caravella 9.5 with Michelin Pilot Sport 275/35-19. There was clearance when the car was stationary but the tire dug a fairly nasty groove in the liner after a few miles of driving.

OK so those are from the XK...

The chap in the UK also ran some 18" staggered XK wheels on his & it didn't rub, but he didn't like the look of the 18" so he put OEM 20" x 9" & runs the 285's on them. No rubbing...

So i think it's possible, i'm just going to have to use spacers on the back.

Seems that Wald fits a 21"x10.5" with 30 Offset on the back of thier Black Bison, running 295/25 tyres, so 295's must be possible!

JAGUAR XJ X350 SPORTS LINE BLACK BISON EDITION ~'07

And Arden offers a 21"x10 with 50 Offset... http://shop.arden.de/jaguar/xj/xj-35...x-21-et50.html

Hmmm....

So I bit the bullet & bought some staggered Arden 21" rims.

I've been in two minds if I should put them on or not, but since nobody was interested in buying them, i've decided they'll go on once the car once it makes it down to Australia.

Here they are, Arden 21" Sportline's suit X150 XK/XKR and X350/358 XJ.

2x 9Jx21 ET40, 2x 10Jx21 ET50, so a staggered set 9" front & 10" rear.






Click this bar to view the full image.













The blue is the protective film, which will come off once the tyres are on.

These will be mounted with 255/30R21 for the fronts, 295/25R21 on the rear.

Can't wait!

Just need a J-Complete bodykit to go with em...i'd better buy some lottery tickets...

I can't wait for the pictures! I really like the Arden wheel style on the XJR. CONGRATS!

I'm also wondering what will fit under my XJR rear 285/35 or 295/35 but on 19's. I just can't seem to find a definitive answer on the offset range.

I know two guys in the UK who have run X150 XKR "Venus" wheels on X350's.
18"x8.5 with 46mm offset on the front. Rears are 18"x 9.5" with 35mm offset.
Stock size for the XKR are 245/45ZR18 front & 275/40ZR18 rear.
One bloke has run 285 on the rear with the Venus 18"x9.5" ET35 no issues.
I think 295 is a stretch on a 9.5" rim, will sit much nicer on a 10"

REally like that style of wheel...sure to look great!

Great looking wheels can't wait for pics, I was thinking of changing wheels but I really like the stock wheels on my XJR so thinking of using 1 inch spacers to get a staggered look. Just need to find some good quality spacer suppliers.

I have a question about tires. I got a 2004 XJR with factory 19 X 8.5 rims (255 40ZR 19s). My original Pirellis naturally wore out. I replaced with ECSTa 4Xs trying to get the same wide tread width and beefy stance as the Pirellis,,No luck. Not the same. So I am asking if anyone has suggestions on what tire will give me the same or wider stance on the original rims without paying the Pirelli tire price?

I thought the center bore on the x350 was 74mm?

I'd be very happy if I'm wrong because that means that rims like the Takoba should fit without machining.

X350 has PCD 5x108, Center Bore 63.4mm

It's the same as the X-Type, S-Type, XF, X150 XK and X351 XJ.

I currently have XF/XK wheels with winter tyres on the car, bolt straight up.

That's excellent information, thanks!

Next stop - offset. I have a set of OEM 18x8 Prestiges on my x350 Super V8 (same brakes as the XJR, so should have the exact same issues with clearance) that I'd like to swap for something more, well, inspiring. I have Tucanas for the winter tyres but for the upcoming summer, I can't really decide if I should go the elegant route with something multispoke like the Coventry Whitleys, Sepangs, AEZ Valencia, TSW Silverstone or the racier way with fivespokes like the Takobas and Customs. Maybe even Tobe or Pegasus (the SO likes those). However, most sets I find are either all 8.5 (which I don't want to put anything wider than 255s on) or staggered with wildly varying offsets and as I plan on having at least 265s in the back, I'm nervous of what a ET20 or even 30-35 will do to my fenders. Tire/rim calculator with offset here: Custom rims, wheel tire packages for your ride - RIMSnTIRES.com

I apologize if I'm hijacking the thread here, but I figure it's sort of on the topic of fattening the rears (and I wish it was as easy as fattening my own rear). :-)

So I need to revise this statement.

I actually have a set of XKR Venus wheels on my XJR at the moment.
As stated before, 18x8.5 ET46 on the front. 18x9.5" ET35 on the rear.
Running Pirellis, 245/45ZR18 front & 275/40ZR18 rear.

The rears are rubbing on the plastic wheel arch liner. I don't know why that bloke in the UK had no rubbing...maybe because the rear wheel arch liner is different between the X350 and X358? Who knows, all I know is the XK wheels don't work on the back of my XJR...

If you go 10" or 9.5" on the rear then you need at least ET50, maybe ET55 or ET60 if you can find it. A too-high offset can eventually be solved with a spacer, too low and there is nothing you can do about it.

The stock XJR Sepang is 9" with ET49, the Arden Sportline is 10" with ET50. That's the region to be looking in. ET35 is too low for the rear...

That means my plans to get the Coventry Whitleys in 19x8.5 front and 19x9.5 rear won't work since they only make the 9.5 wides with ET25. Too bad, but very good to know.

Well guys I tried a 19"x10" ET46 on my 04 XJR rear today and it will not fit .....grumble. Its just about against the plastic liner. So I take my nice new unmounted Michelin PSS 285/35-19 (waited over two months for them) and shoved one underneath and it also doesn't fit between the inside plastics and fender lip ....."edited words".

So gents the question is there a simple way to unload the air springs so I can measure things at max travel upwards? LOL I thought this would be rather simple over a limited slip install!

I'm also wondering if the fender well plastics are different on a X358 vs X350? Or even the rear end.


-K

The easiest way is to remove the height sensor link to the suspension
Then just move it down which will tll the air shocks to go up
You will need the car on the ground, engine running and do both sides so it is even

Cheers
34by151

Nice wheels! How much is Arden getting for a set of those?
Vector