I'm pretty seasoned with Jaguar's have had two X150 XK coupes '07 and 14, 2 X350 sedans and 2 X350 XJRs but I'm not super familiar with the XF. I'm looking for a sleeper vehicle that is fast and it looks like the V8 supercharged would fit the bill nicely. Question is opinions on going with the 4.2 or the 5.0 I'd like the fact that the 4.2 is torquier on the low end and I think the the reliability factor is better than the 5.0 but I also like the power of the 5.0... I would definitely be doing a 1.5 lb pulley and tune for either or, let me know your thoughts and opinions. Thanks

 

I have had both engines in R form and the 5.0L is the winner. Especially if you plan to modify. The 5.0 SC is just way easy to get to 600+ with a lower pulley and tune. Plus more if you want it.

But I suggest you should drive both before deciding. The 4.2L is a great engine.
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You need to drive a XFR 5lt supercharged, when you do you won't bother with the 4.2.
I am fortunate to have a x308 XJR, a XF SV8 4.2 SC and a XFR which out performs the others in raw power.

 

Great, thanks for the info. Unfortunately my budget is around 12k so I'm limited as far as getting a 5.0 SC

 

5l has more power, 4.2 with pulley and a good tune is basically the same as an stock xfr but you hit a wall.

5l needs a lot more money put into it, big things are chains injectors and the coolant gravy work. if you ever overheat you may as well just pull over at the side of the road and burn the car down it’s totaled

 

Yes, I agree. I already have an AMG that runs the low 3 seconds 0/60 in low 11s in the quarter... Just basically looking for something that's pretty fast...Keep all these pesky highway cars with punks driving them at bay... So if I do hit a wall with the 4.2 I would be okay with that topping out at roughly for a 470 horsepower with the tune and pulley... I've heard a lot about the timing chain issues. At what miles does that usually raise its ugly head?

 

Also another question in comparison a newer 3 0 SC with a lower pulley and tune. How would that compare to a 4.2 l with a pulley and tune?

 

The 4.2L is much better about the tensioners and all that. Not perfect but way less problems. I took my 2005 STR to 132K miles with no noise and any other problems.
That's what's so surprising about all the 5.0L timing chain/tensioner problems? Jaguar solved them after the disastrous 4.0L mess on the 4.2L then again fell apart when the 5.0L came out?
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Pulley and tune on the 3.0 is suppsoed to be 460HP. I have that (and more) and feels like about 400-425. Im going to get it on a dyno soon

 

Bought a XFR!