Hello, does anyone know the front and rear offset for the 20" Senta wheels ?
Thank you...

 

I'm not a big fan of Senta wheels, but what are we talking about here? The 4.2 years have a different offset than the 5.0 years because mostly E-Diff.
For a 2010+ the rear offset is E46, or 46mm.

 

I think for all years, the front offset is 49mm.
For the 4.2 models, the rear has a 23mm offset.

 

49mm front offset is correct for all years.
Rear offset is 26mm for 2008 and 2009 4.2L XKR models equipped with the Alcon Performance Brake Package. I'm pretty sure that's needed to clear the larger rear 4-piston caliper.

 

26mm is for all 2007-2009 X150 rear wheels regardless of brakes.

 

Oh well, just can’t trust internet seller listings.

 

Technically, still correct though. That statement never excluded other models.

 

I defer to jahummer's superior knowledge and experience and stand corrected. Until now, I thought that the reason for the Selenas was to clear the Alcons and that's why I thought they had a different offset. So I guess that all the 2007-2009 20" OEM wheels will fit Alcon- equipped X150s, not just the Selenas.

I got thrown off by all the trouble Richzak went through to buy a set of aftermarket wheels. He owned a 2009 XKR Portfolio with Alcon brakes and bought a set of 20" wheels from Coventry Wheels, a Forum sponsor that specializes in aftermarket Jaguar wheels. He was surprised when the rears didn't fit because they didn't clear the caliper. Richzak eventually had Braelin wheels made with custom offets. He could have saved a lot of time and effort by buying a different style OEM wheel.

 

Not to linger off topic too long, but the challenge with wheel fitment on Alcon optioned XKRs is primarily in the front as the radius from the hub to the top of the caliper is about 221mm which leads to a diameter of approximately 442mm, largely due to the 400mm rotors. There are indeed many aftermarket 20" wheels that will fit the front with no issue as long as the barrel diameter is greater than 17.5" and offset/backspacing is sufficient to clear the face of the calipers, which most are. Many cast wheels feature a stepped barrel design and some have inset tire valves which further reduce barrel diameter. Some rotary and most forged and OEM wheels have smooth barrels, so clearance is not an issue and even managed to find 19" wheels that clear the front calipers as well. The rears are no problem as the rotors are only 350mm. Since little information was available regarding the measurement specifications of this brake package to the aftermarket, I had to spend an exhaustive amount of time reviewing wheel specifications to confirm which would or would not fit and to my surprise, did find a considerable amount of options available.