[quote=Akers04Coupe]Did a search did not come up with a POSITIVE answer...

Was thinking about going 225/40/18 and a 275/30/19...What is the biggest tire I can run on then factory OEM NA rims without having rubbing or clearence issues..ordering a new set and wanted to go bigger. Can the front be bigger than 225/40?

Hi Jason

im not a know it all when it comes to the XF. however as a previous sales rep for Continental tyres here in South Africa i can simply tell you it has all to do with over all diameters. there is a simple calculation to use

if your stock fron rims are 225/45/18 the calc goes as follow
225 X 45 % X 2 = 202.5mm (tyre diameter/aspect ratio)
18" X 25.4mm = 457.2mm (rim diameter)
add these together and you will have 659.7mm overall diameter. measure as inner maximum casing ratio

the general rule is that for vehicles with tire persure sensors not to excede 9mm overall diameter up or down as this will raise a fault code and illuminate the dash warning light.

that being said if your XF does not have any tire presure sensors like mine then exceding 15mm overall diameter is seen as max increase.

after 15mm you will see effects like:
premature wheel bearing wear
Speedo inconsist with actual speed (XF generly almost accurate)
premature ball joint and tie rod end wear.

I did the calc for your suggested 275/30/19 and yes if NO wheel sensor is presant then you can fit them to your XF. as for rubbing the inner linning of the mud guard. this is generaly seen when running negative camber. the MB is renouned for becoming negative due to the rear suspention tolerances. your local tyre dealership will be able to sort this out.

I have stock 225/45/18 front and 255/35/19 rears (continental sport contact 3) and have just under 35000kms (about 21 000 miles) on one set with 5 mm thread left. i do my tyre persures every week and alignment every month.

i hope this will answer your question to some degree

Athol

 

to the OEM wheels, you can safely mount a 315 nittos. I along with many others have done it when i had my cobra with 9" wheels. However, i can't say anything about rubbing to the fenders with xfire. it was perfect with mustangs.

 

Hi,
Do not go 275/40/19 it will not work

I did 255/40/19 and this is ok 155+ in 30 or 35 will work but not above

I am in Houston, roads are shitty so I had to go to 40 in the back. I might see what`s next for the front to have more comfy feelings for the front

So No 275/40

I recommend Sumitomo and Falken 452 and of course Michelin Pilot sport A/S plus the best.....

Max

 

you can run up to a 315, i run 25 series sidewalls, I dont care what the ride quality is like as long as it handles

 

i run the falken 452 tires and they are great. why do you want wider tires so bad? i think the stock ones are wide enough. umm valk has bigger ones on his car... you might wanna send him a message and ask him.

 

I've been running the Toyo Proxes T1R (225/40/18 F and 275/30/19 R) for the past 2 years and about 35K miles. Absolutely the best tires I've ever had; sticks like glue and rides well with near neutral handling during high G turns.

Issues? The rears get a bit noisy at their end-of-life, the front is a tad taller even though they calculate to 25.1 F and 25.5 R, and lastly, they appear to be back-ordered to the manufacturer and won't be available for weeks or longer.

 

I run Handkook V12 evo on SRT-6 wheels and have never had a rub. No spacers necessary. Front>235-40-ZR18 ... Back>285-35-ZR19 Squirrel Crusher

 

[quote=laitsabr]After reviewing the valuable experience shared here, I just ordered my stock wheel tire replacements:
F: 235/40-18 - curious to see how much rubbing will occurs
R: 275/30-19 - needed to sign a waiver as it is "2% more than recommended size"



This sounds like a good plan...how has this worked out since the installation?

 

Just installed Falken Koblenz 19X8.5 in the front and 19X9.5 in the back. Matched them up with Pirelli P-Zero 235/35-19 for fronts and 275/30-19 for rears and no issues at all. Just purchased Eibachs but looking for an installer in Miami so I'll see what issues if any I'll have once I get the springs installed. If anyone can recommend someone in the area let me know...


Thanks...

 

Could you post a couple pics of the new wheels/tires? Thanks

 

I am curious at to how much room you had between the inner tire sidewall and the upper control arm nut? My springs have settled a fair amount and w/o a spacer on the front a 235/40/18 was very close to rubbing the control arm nut. With the spacer installed it was fine with no chance of rubbing and possibly tearing the tire on this nut.

Having said that, with the 12mm spacer that I have installed on the front with this same sized tire, I get a slight rubbing on hard, rough corners (a nickel sized wear spot) on the inner front fender wells.

As a side note the car looks a ton better with 12mm spacers on front and 15mm spacers on the rear when running factory rims. It is a "must have" appearance mod, especially for the rear of the car as the factory rims are tucked too far in.

As I understand it, the factory NA and SRT6 rims are the same size and offset, just different spoke design, so what works for one model will work for the others.

[QUOTE=Cincinnati Slim]KrzyFast

 

Here ya go...more pics in my gallery.




MannyTwoTwo Gallery - CrossfireForum.org Gallery

 

Manny, those wheels look awesome. The Eibachs will definitely finish the look off for you. What size spacers are you using? Looks like the front is spaced just right, but the rear looks like it needs to come out a bit more. Looks like possibly 10MM on the rear?

 

Thanks...I don't have any spacers but the rears could use the 10MM. Once I find someone to install the springs I'll make a decision on the spacers.

 

Ahhh...... I had to look again, because I thought I saw spacers on there, but it was the polished hubs of your rotors that I was seeing.

 

Run the Handkook Ventus V12 evo 285-35-ZR 19 on the back stock rims and you'll never have a rub problem. Squirrel Crusher