The 18 inch wheel and tire assemblies weighed in at 54 pounds each, the 16 inch wheels with tires are 40 pounds each. It is like removing large moments of inertia, reducing the rotating mass of 4 heavy flywheels. No longer need to spend $250 a tire.
Still have the 13 inch front brake rotors. Might be able to fit some seriously light weight 15 inch racing tires and wheels if I down size to 12 inch diameter rotors, but real spoke wire wheels might look pretty sharp someday.

 

And a much smoother ride as well. I love 16-inch wheels for their ride, their greater number of tire choices, their significant decrease in tire prices, and their longer treadlife. Most folks will frown on the appearance but who cares what they think. Enjoy your practicality....

 

Not bad. While I wouldn't do it, the color and the wheel type, gives it a late 80's Aston Martin Vantage feel.

 

You might want to search the forum for a post by mrplow58 regarding 16" Dayton wire wheels he fitted to his car. I just purchased some 17" Dayton wires on ebay which were off a 2000 XJ8 being delivered tomorrow. I'll post a picture when I get them sorted out and fitted.

 

I'll bite. What car are those rims from? I wouldn't do anything soon (new tires), but I'm going for a XKE vibe on my XKR, and the larger diameter wheels detract from that. Just saying.

 

Given the same outside diameter, a short sidewall tire has a larger moment of inertia and is heavier simply because the steel beaded thicker part of the sidewall now has a larger circumference.
Obviously an 18 wheel also has a larger moment of inertia and larger mass than a 16 inch wheel (26 versus 19 pounds in the case of the Jaguar wheels I sampled). We are talking about the rotational acceleration of Four Flywheels every time we move the car. Larger brakes are required just to handle decelerating the increased rotating wheel inertia. Jaguar puts Brembo Brakes on cars that are ordered with the 20 inch wheels.
My 18 inch Jag wheel and tire weigh 54 pounds, the 16 inch Jag wheel and tire weigh 40 pounds.

Does anyone know how much a 2003 Jaguar XKR 20 inch rear wheel and tire assembly weighs on scale off of the car?
Thank you,
Mike

 

I think the look really suits the XKR. The wheel well arch proportion/fit is very good. The XKR body lends itself very well to many different types of wheel styles. Good job.

 

You will go up in weight with wire wheels. Theyre all steel, dont stay balanced and true unless you drive were roads are perfect. Larger brakes are not only to handle rotational mass but mass and speed period. Slowing the the car much faster than std brakes. Jaguar has also used larger rotors on the std brake package to increase exerted braking force and shorten stopping distances using the less expensive std brake package.
But then again if i was concerned about practicality and not looks and performance i would have bought a prius. Especially since i drive 80 miles round trip a day.

 

I really like the wire wheel option for appearance also, about the only way I would compromise the losses associated with an extra heavy wheel. Would prefer to try to make a 16 or 15 inch wire wheel fit the XKR. Just don't know which of the wire wheels made are more likely to stay round and withstand some occasional hard driving, including the 1/4 mile runs with a 370 HP Jag V8.

 

XJ8 16 inch rims fit XKR, with slight front caliper mods. Or easier yet, use the 12 inch XJ8 brake rotors and caliper brackets to fit the 16 inch rims with plenty of clearance.

 

All good points. The wire wheels I purchased weigh in at 30 lbs. each which probably is not that much heavier than the stock Lamina wheel. Here again, most upgrades involve some level of compromise, in this case aesthetics vs. practicality/braking performance. I obviously made that choice, which I may come to regret. That said, it wouldn't the first time I made a questionable decision, and most likely will not be the last.

And it's fun!

 

I just like the look of bigger wheels, but I see your point and it doesn't look bad. I like the idea of a list of cars you've owned. I'll try that myself.

 

Even if a 16 inch wire wheel weighs 30 pounds, because The mass is distributed closer to the axis, it would require less horsepower to accelerate the 16 inch wire wheel than what would be required to accelerate a 20 inch diameter, 30 pound aluminum wheel. If the the lateral and radial runout of a 15 or 16 inch wire wheel did not exceed 0.06 inches, you probably would not notice any vibration or shaking.
Given that the XK8 was inteneded to embellish the the XKE, I think 15 or 16 inch wire wheels would look uniquely beautiful on an XKR or XK8.

 

I'm having a little trouble believing that my 17" wheels and tires weigh somewhere between 40 and 50 lbs. I could swear it only feel like 20 lbs when I lift them.

 

The previous owner of my 2000 XK8 changed to XKR wheels which are one inch bigger in diameter, I believe 18". I have never like the ride and am coming up on needing new tires. I also don't like the looks of the standard XK8 wheels used in 2000. 16 inch wheels sounds like a pretty good idea. And cheaper tires with better ride may be worth the effort.

 

The mass/inertia benefit discussions are all sound, but the higher sidewalls may hurt lateral stability. If you're not into the performance aspects, then who cares though. Personally I like the look of the higher sidewalls - classic. Nice job!