I swiped this photo from another section of Jaguar Forums.

As I have a very similar XKR I can't help believe this example sits lower than stock...

Which I now know a little more about how "this is sometimes done".

I am a proud Dad who's son now works in the auto industry in a marketing role and has what would have been for me a "dream job". I sold Hot Dogs and Cheese. Not nearly as sexy.

As I write this - he is knee deep in finalizing a Super Bowl ad.

Anyway... he showed me some "behind the curtain" details of how they make the cars look so good - and one example (maybe same in my example) they load them with a lot of sandbags.

So now I see pictures like this one and I wonder.... "How much sand?"

 

I had an Alfa Romeo 25 years ago which I lowered but the rear didn't lower as much as I wanted so I put a bag of sand in the trunk and voilá, the car got the perfect stand!:-)

I've got lowering springs ready to assemble from Adamesh which should lower my Jag 25mm but if not I won't be using sand bags on this car!:-D

 

Not a fan of the lowered look. I think Jaguar got it right from the factory.

 

Maybe lowered looks marginally better, but I cannot imagine how many more things I would hit - curbs, parking blocks, steep hills changing to flat surfaces, speed bumps - if my car was any lower.

 

Folks lower them to get rid of the fender well gap. I went with taller tires. Better ride and no bent rims is a huge benefit.

 

Find out what the spring rates are, then determine how much lower than stock the car is, and there's your answer.

Example:
100 lb/in springs on all four corners.
The car sits 0.50" lower than stock.

100 lb/in * 4 springs = 400 lbs. total to get the car to lower 1". To get 0.50" lower, you'd just need 200 lbs.

So, find out what the spring rate is for the front, double it, then find the rear and double that, add them together, then guess how much lower the car is from stock and there's your fairly accurate rule of thumb.​​​​

 

I think it depends on what you do. A small drop can be good, exceed 3/4" and it starts to look bad.

For me, there are these tire stopping curbs in several parking lots I use. They are made for family haulers where drivers don't pay attention. A lowered car the size of an XK will be outside the parking spot at the rear if I can't cross that curb with the front spoiler.

 

aslo agree.

Curious, What size did you get?

 

Exactly, looks so much better with a smaller gap! :-)
Taller tires will make the speedo show a lower speed.
I've never had a bent rim with any of my cars with big rims. Knock on wood! :-D

 

I like the look where the gap between the tire and fender wheel well is about 25mm. This being said I won't lower because it stiffens the ride more and it invites undercarriage damage .

 

Probably not the best pics but... 275/40R19's in the rear and 245/45R19's up front. OEM from a newer XJ with 20mm spacers in the rear.

 

Although the ride with 20s and low profile tyres are nice I bet your xkr would be super smooth on the road now ..good idea

 

Question for those who run their XK's on the track, but first an opinion.

I agree with Ranchero that closing the gap in the well improves the look so lowering has that effect. I also agree with Steve that the 20" wheels improve the look, but imo lower springs, 20" wheels ruin the "Jaguar experience" in terms of ride quality and comfort.

I've heard lower spring improve cornering but 95% of my driving isn't affected by that. Does it improve handling and is it worth the harsh ride?

Also, as I don't race mine, do the 20" wheel impact your times or is that strictly tire surface & type/ road surface (all other things being equal)?

Not being critical of others choices, just asking.

Ranchero, those Tobia's you have on the same width front and back? I had those on my SV8.

 

Not quite correct. Due to suspension geometry, the actual spring rate is not the same as the effective spring rate at the wheels. A lower control arm is a lever, like a motorcycle swingarm.

 

I've never driven one on the track with anything but the stock 20" - I now have 305 Pzero rear and 265 MPSS front, but I had the standard 295/255 Pzeros on the Nürburgring and it stuck like glue. The limiting thing on lap time was the diameter of my cojones, not the wheels.

 

It all depends on what your ideal set-up is.

For me, although the ride was ever so comfortable with the standard springs, when pushed the understeer was just too obvious (yes granted this is a GT) I needed something that would handle a lot better hence why I went with a set of performance springs.

The trade off is I do lose some comfort especially when travelling over speed humps & pot holes but the handling is so much sharper now its not a lazy XK anymore.

On the open it would be hard to tell the difference between the stock spring and performance spring as it rides very smooth.

Having said that a good compromise would be the performance spring riding on a set of 19s that would give you the best of both worlds.

 

Sandbag free