hi,
I am thinking of up sizing my rims to 20' vossen cv3 with low pro tires. Currently i have jaguar 19' wheels. I want to know that if the suspension on the xf is air suspension also would up sizing cover wheel gap or would it make the car look lifted. If i have to lower it best way to do it and how much would i need to lower it just want the wheel gap covered.

 

Get the 20's and then get lowering springs. Will eliminate the gap for sure.

 

I would advise against upsizing tires and wheels to get rid of wheel gap. You probably want to get rid of at least 1" of gap, which means a tire 2" larger in diameter. It will effect your ECU, lower acceleration rates and if not using lowering springs it would make the car look like a 4-wheel drive.

If you do it and try compensating with lowering springs you need to lower the car 1" to be where it is now with the present wheels and tires. When you install lowering springs without new, shorter shocks, your total shock travel will be limited, which means you can bottom out hitting pavement joints. Bottoming can destroy your shocks as well as create dangerous handling.

 

I upsized my wheels from 18" to 20" six weeks ago, going from 45 profile tyres to 30 at the rear and 35 at the front, and the overall diameter was a bit less, and hence the wheel arch gap was a bit more, about 3mm I think.
I fitted the Eibach lowered springs package two weeks ago and now the wheel arch gap is much better (smaller), especially at the front. The gap is now about 1" at the back and 1/2" at the front. No problems at all so far with bottoming out. The Eibach kit is 1.2" lower springs at the front and 1" lower at the back, which gives the car a more aggressive but slight 'nose down' look, and also allows enough room at the rear to cater for passengers & luggage without bottoming out or scraping on the guards.

 

Hows' the ride quality?

 

Ajay, please keep in mind that larger rims does not necessarily mean less wheel well gap. What you really want to look at is the overall diameter of the tire (not rim) to get an idea of how much gap that you are going to loose/gain with a new set of tires. Now, as a general rule, when you go with a larger diameter rim, you are almost forced to go with a larger diameter tire. You can only make the sidewall so small with a car like we have. Also keep in mind that if you drive where the roads are less than great, going with the larger diameter rim is most likely going to result in an increased likelihood of ending up with a damaged rim. So, keep that in mind too.

As for making the car ride higher, like was mentioned, to take out 1" in the wheel well gap, would mean making a 2" larger diameter tire, which then means that your car will sit 1" higher off of the ground. Also, running the larger diameter tire will also mean that your tire edge turns in a larger arc when you are turning the car. This can lead to rubbing on various body parts which in extreme cases can lead to a tire being cut down (a lot of states require the tires not to rub at all and that aspect is checked during the state/city inspection). So, what this really leaves you with is trying to figure out how to go with the larger diameter rim while keeping the overall tire diameter nearly the same. Not a difficult thing to do. The easiest thing to do is to have the same size tire you have on the car now brought down off of the tire rack and then start looking at the new tires you would be getting and putting them side by side. It will then be pretty obvious which one is taller (larger diameter) and also if you are going with a wider tire how much wider it is too.

Granted, if you start playing with changes in width, height, and rim offset, it can become very confusing as to what caused your problem and it can get even more expensive to fix your new tire rubbing issue. This is where proceeding with caution and doing some very detailed calculations on how far the rim is moving, the change in tire diameter, the change in the tire edge arc, etc can save you lots of time and effort. I have been down this road as I am known in the Ford Expedition groups with my truck as I have managed to run 37" tires (on 16" rims) with only a 4" lift. Most say that it is impossible to do. I did it. But, I also have very little error as things come to within fractions of an inch in a lot of cases and also knowing where you can gain a little bit more through some careful body work.

 

There is a wheel and tire calculator on this forum that can illustrate the changes.
Look under the "tools" pull down tab just under the forum website header.

 

The ride quality is only marginally worse than before, just a tiny bit harder.
I'm already used to it, and it's well worth the improvement in looks & handling.