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If my 2016 XJL was originally ‘fitted’ with 20” wheels and the wheels/tires were refitted with 19” wheels, will the original spare tire be appropriate for the 19” wheels/tires when it might be used? Thanks,
Great question! Wish I knew the answer. What I would suggest is calculating the diameter of your road tires, and the spare, and then seeing what the difference is.
From what I know, I believe, the spare is the same for all XJ wheel options as it's not dependent on the wheel size as much as it is based on the circumference of the tire tread.
I think it should be the same too as tire size should dictate the size of spare, not rim size.
That being said when I bought my used XJ it had the wrong size spare in it (One inch too small total diameter). Driving on it caused traction control warning to turn on and limitation of my speed. I instantly turned back to the tire shop parking lot and left it there. I didn’t want to mess up the differential. Measurement confirmed it was incorrect.
I would measure the diameter on your new rim after mounting a valid tire to confirm they are the same as the spare.
This is a picture of my spare wheel that doesn’t work. What tire do you have mounted? Is your spare also 19”? Thinking I should be able to mount a new tire on this rim and be fine. Hopefully this will help OP too.
Calculator above suggests I need 140/70 R19. Is this what everyone else has?
Sorry realized I may have wrong regular tire. This is my rear tire.
EDIT: Now I'm even more confused. I have all the correct tires (see manual page on tires below) and yet they are not the same diameter. What gives? BTW I have the supercharged version of the XJ.
If my 2016 XJL was originally ‘fitted’ with 20” wheels and the wheels/tires were refitted with 19” wheels, will the original spare tire be appropriate for the 19” wheels/tires when it might be used? Thanks,
If you replace all 4 of your original 20" Kasuga wheels and tires with 19" wheels, your original 19" Space Saver spare wheel/tire will still fit but you'll probably throw an error code and disable the TPMS. To prevent that from happening, you would have to replace that 19" spare with the 18" spare/tire as shown in the chart you posted.
Why do you want to replace your 20" wheels with 19"? Are you sure that 19s will fit over the larger brake rotors that are fitted to the 5.0L SC models? If you're looking for a more comfortable ride quality, get rid of the OEM Dunlop Sportmax tires. I have the same Kasuga wheels and am pleased with the ride quality of my Continental Extreme Contact DWS06 tires.
All the normal wheels have a diameter of ~700mm regardless of rim size. All spares listed have a diameter of ~670mm. So every combination will be 30mm (more than an inch) off in diameter regardless of rim size. I think the difference in rim size of the spare between models is to clear the bigger brakes on the supercharged car, not to change total diameter. So in theory the 18” spare can only be used on the NA car; 19” can be used on both.
The 30mm difference between the normal set of wheels and the spare is not a big deal if your spare goes on the front if you have rear wheel drive. But the difference triggers the traction control continuously at speeds above 25-30mph if you put it on the rear driving wheels. The all-wheel drive variants are probably bad at every position. This would likely put the differential under high stress if you drive the car even a couple miles. It didn’t sound good on my car. I guess you could roll around at < 25mph or deflate the tires on the other side to decrease the difference.
It looks like spare tires are sold in only a few sizes worldwide, so Jaguar used a standard size even though it doesn’t match the other wheels. I assume the trunk space was more important than a proper spare tire. Still I don’t know if I’ll ever trust using it again, except for maybe on the front.
Has anyone else used their spare on the rear wheels before?
05-26-2019, 07:14 AM
