after all the sweat and headache(I will write a separate post about that) , I finally was able to put the 20" Senta chrome wheels on my XJR .with 1.25 wheel-adapter

now I found the front tires are rubbing wheel arch liner wall a bit ,not the outer arch so I am not sure know rolling the fender will resolve this rubbing issue.

 

keep the car original... no headaches then.
customisation becomes expensive
Peter

 

If it's just hitting the liner and not the actual fender lip, rolling won't do anything for you. If it bugs you, you'll have to clearance the liner a bit, which means you'll have to do some cutting and fabrication on the liner. It's not really a big deal if it touches the plastic liner a little bit, as long as it isn't rubbing REALLY hard. The X308 has fairly small wheel wells, so some rubbing is likely to happen. The 18x9.5 wheels I'm running rubbed just a little when I first put them on, but they clearanced the liner on their own after a little bit

Another option is thinner adapters. The thicker the adapter you run the more you increase the arc length of your wheel sweep and the more likely you are to rub. If you were to go to a thinner adapter you shorten your arc length and you'll rub less. This has to be balanced though with the offset you're going for. I assume you're running the "front" Sentas, the 20x8.5 +49s? The OEM Asteroids are 18x8.5 +33, and there's quite a bit of room to space those out. So since your current spacers are 1.25" (31.75 mm), your effective offset is 17.25mm, which is VERY aggressive on an X308. If you go to 1" (25.4 mm) spacers, that gives you an effective offset of ~24mm, so a nice 9mm increase to the outside, and this would probably fit quite well. If you wanted to go a little bit safer yet, you could run 20mm spacers, which would give you an effective offset of 29 mm, which would almost certainly fit, but won't look as aggressive, although slightly more aggressive than the stock XJR wheels.

I've used this company's adapters in the past, and they've always worked well for me.
http://www.performancewheeladapters....-SKINNY/Detail http://www.performancewheeladapters....8-Wheel/Detail
Good luck

 

Cab,thank you for your great reply. I put the adapters because the change of bolt pattern and most of them in the market don't come with born-hub 74.1 but smaller, I am measuring my options if I should look for the thinner one

btw, I rolled my rear fender I hope it will prevent rubbing but I am still concerning while I am making a hard concerning.

 

It adds some to the cost, but any machine shop can expand the bore on the adapters. I did that on the wheels I'm running and that was about $20 a wheel. It should be cheaper for the adapters, as a bunch of the cost with the wheels was just the time to get them fixtured up. Also, a lot of these adapter places build on a per order basis, so you could probably ring them up and see if they'd just go to 74 mm instead of 73. It would probably be low cost or maybe even free, as it's likely just a quick revision to their CNC program.

But in any case, post up some pics! The Senta's were one that I had been considering when I was changing my wheels, so I'd love to see how they came out on yours

 

yes,CAB.

My adapters are "special order" for 74.1 bore hub. and it drove me nuts to find the correct open lug nut . adapters came with 12.5mm nuts but not I finally found the X308 has usually 1/2X20 nuts.

I will post the wheel swap soon