I currently own an XJ8 2004 which I love but which has given me a few problems recently. Hopefully it will be fixed in about 3 weeks (waiting for part from UK).I am looking at the XF 5.0 Premium Lux as a potential replacement.

1.Should I go for a 2011 or wait till the 2012 is a bit older.
2.Are there major differences between the 2 models apart from cosmetic ?
3.when did the 5.0L engine replace the 4.2L and again did it make a big difference ?

 

You will absolutely love the XF regardless the model you decide to purchase.

First, it comes down to preference. Monetarily, it will just be $2,000-3,000 difference.

Second, i don't think there were any MAJOR differences, hopefully someone else can chime in on that.

Lastly, Jaguar started offering the 5 liter in 2010 on Premium models only. All the other models still had the 4.2 liter engine. 2011 + models got the 5 liter regardless of the trim. The 4.2 was no more....
And, YES! The 5 liter is so much better, that it's not even comparable. The power delivery is just amazing on the 5 liter direct injected engine.

 

My cousin in the UK bought a 2010 3.0 diesel. Then he traded that for 2012 portfolio 3.0S diesel.
He says the numerous refinements to the 2012 make it a different car.

I rode in his car earlier this year on our trip to the Jaguar factory. It s definitely worth buying the 2012 if you have the choice.