I must have driven a dozen X150's over the last couple of years, mix of 4.2L XK, 4.2L XKR, 5.0L XK, 5.0L XKR, dead stock, tweaked and tuned, and in between.

It always seemed to me that the 5.0L X150's felt "heavier" than the 4.2L's, even though they are the same body, same interior, same weight... the 5.0L cars just felt more weighty.

I think I figured out why after driving both 4.2L and 5.0L today.

The spring on the 5.0L accelerator pedal is stiffer, the power steering is heavier on the 5.0L, and the steering wheel is thicker on the 5.0L too, makes the 4.2L feels more light and nimble to drive in comparison.

The pedal box was also revised on the 5.0L and so the pedals are in a slightly different position, as well as the weight of the spring. Jumping between the two cars it's a bit of a strange feeling.

Funny how they are the "same" , but not the same. I wouldn't say one is better than the other, just different.

It was something that always bugged me, but now I know...

 

That is an interesting observation. Jaguars used to have light controls and was always a criticism reviewers would make, especially about the steering. However, in everyday driving when one wants to make smooth progress, that is not a bad thing. It means less effort but one has to be a little more precise with one's driving too. My S-Type is more like that.
Road testers seem to want to take every car by the scruff of the neck and wring out the last drop of whatever they are looking for. Light controls don't respond well to such treatment. I expect Jaguar responded with the facelift by tuning out some of the traditional Jaguar-ness and making it a little more like the competition and what people were expecting (heavier controls, stiffer springs, louder exhaust?) - resulting a heftier feel.
Your summary could be additionally helpful to people who want to know the character differences which we often fail to convey

 

I had a similar thought.
The 5.0 even after years of owning it, feels somewhat unnatural and not in control.
I was able to put my finger on it.

When driving in a spirited manner I have always subconsciously wanted to know where the gear lever is.
Driving with paddle shift or the rotary knob, I am deprived of a vital feedback and sense I was raised with.

 

I was in the US recently and hired a Mustang 5 litre for the two weeks that I was there. When I got to the first corner in my '10 XKR after not having driven it for so long I almost went off the road the steering was so light!

I also find the steering on my wife's Audi S4 very heavy in comparison.

 

THIS!!! I am not fond of the rotary knob shifter, or "piano" push buttons that are in some cars. I drove a manual for ~90% of my life. I still like to "grab the shifter", even in an automatic.

And yes, the steering response is incredibly smooth and quick. (except when it is "shuttering" at low speeds )

 

I'm sure there will be plenty of blow-back for this comment, but imma gonna say it anyways...

The 4.2 is more of a "woman's car" while the 5.0 is more of a "man's car"!

 

Our 5.0L XK is my wife's car. You calling her a man?????

 

So by having a 4.2SC does that mean I'm a manly woman?

 

How about: "The 4.2 is more of a "GT" while the 5.0 is slightly more of a "sports car" (both actually being more GT that sports though)!

 

 

Sooo... if the 4.2 attracts more women, and the 5.0 attracts more men... I'm OK with that.

 

Cambo, were the two the same model? (normally aspirated or supercharged)
Quite a bit more difference between my 4.2 N/A and my 5.0 SC in chassis rigidity.

Also makes me wonder if all the 2nd gen chassis were built with the extra bracing my 2010 has.

 

In my $105,000 sports car I have never been able to do the most basic sporty maneuver I have done in every car...
Back out of parking spot into oncoming traffic and gun it, all in one smooth move.

If its a man's car, its not for any man in a hurry.

 

The 'feelin' is all man.
Primordially man has grabbed thrust control by the palms.
From the reins on a chariot to the thrusters on a spaceship.

 

I will say that I prefer the shifter in the 4.2 X150s over the weird J Gate they had in my X308 and X100. I may have hated my A8, but the tiptronic layout of the shifter itself really was sensible and I liked it. It was slide to the right of drive to go into manual mode, push forward to shift up and pull back to shift down. Obviously my current X3 is shift left and then pull back to shift up and push forward to shift down; not liking that so far.

All of these shenanigans are behind the best arrangement of 3 pedals and a gated 6sp.

 

Manufacturers retain the best minds in the world to help them figure out the demographic.
For instance when Mazda realized the demographic for the Miata, they sold a million of them, say they cleared $1000 on each car, they cleared a Billion dollars!
Whereas had they used an engineer to make the best sports car around the Nurburgring ring, they would have lost money.

JLR realized rightfully that their demographic is not the hardcore enthusiast- who only buy used. Their audience is the executive lessee.
But they throw in some goodies for the devotees so as to maintain the brand and resale values.
Guess the most successful Porsche- hint, wasn't a Porsche at all.

 

You look so manly changing your water pump on the side of the road or riding with the car on a rollback. Having chrome trim around the infotainment knobs makes up for though. LOL.

 

I don't think that has anything to do with the "weighty feel" of the car though.

Whatever you need to get you through the night...

Yesterday it was a 5.0L XK and my 4.2L XKR. But I felt the same differences when I first swapped between the 4.2L XKR and a 5.0L XKR a while back, just couldn't put my finger on it...

The 4.2L XK coupes are missing the strut brace in the rear, but everything else seems to be the same bracing wise on the 4.2L XKR, 5.0L XK coupe and 5.0L XKR coupe. We don't see many convertibles here.

 

This took the OPs post of interest, and suddenly allowed it to be dominated by comments of a child.

 

My guess (really - I didn't check the internet) is the VW Touareg. My daughter had one of the first with the V8 and I told her it rode as stiff as a Porsche. I guess they heard me and changed the badges and raised the price and the rest is history.