I keep seeing occasional postings on what size rims/tires can be fitted to S-types. Below are comments on sizing wheels for you car as well as the factory tire/rim sizes for S-type Sedan sports option and STR wheels.
I want to get this information in one location for future searches.

Key features of S-type wheels and tires:
- For all S-types, all tire ”Outside Diameters” are in the range of 25.6” to 25.8”( 649mm to 655mm)
- To maintain close to a 25.7 tire O.D., as rim diameter increases, side wall profile must proportionately decrease.
- As rim/tire widths increase, overall tire diameter increases proportionately.
OR
- Wider width tires = larger OD
- Larger diameter rims require lower profile tires.

- S-types have very large positive offset on front wheels. All wider rims must stick farther out. Go too wide and you will have to flare the fenders. (Wheel scrub and suspension geometry about the center of the rim will also have to be considered.)
- S-types have large positive offset on rear wheels. 17 x 7.5 ET60 rims have about ½”-3/4” inside clearance. 18 X 9.5 rims are as close as practical on the inside, with ET 49, and will still stick out board about 1.1 inches. A 9.5” wide rim is the max width on the rear without starting to have wheel well/fender clearance issues, or have the rims protrude beyond the fender and have to run a tire with a negative sidewall profile.
- Lower profile tires reduce ride comfort, can increase handling characteristics, and typically have a shorter life. Many performance drivers believe that tires below a 30 profile adversely affects how the car handles and feels, unless the vehicle’s suspension has been designed/set-up for using very low profile tires.
- 20” or larger diameter tires on an S-type will require a 20%, 25% or max. 30% profile. A 275 X 25 X 20 will have a tire diameter of 646mm/25.4" (1% slower than stock diameter) 245 X 30 x 20 will have a tire diameter of 656mm/25.8” (Works/good for front, but a narrow for STR staggered set-up.)

DATA

S-type Sports wheels:
F&R Tire size: 245/45 - 17 X 7.5
Tire OD: 652mm/25.7”
Front: ET 60
Rear ET 60

2002-2007 S-Type R wheels:
Front: 245/40 - 18 X 8
Tire OD: 653mm/25.7”
Rear: 275/35 18 X 9.5
Tire OD: 649mm/25.6”
Front ET/Offset: 60?
Rear ET/Offset: 49

2008 S-Type R Wheels
Front: 245/35 -19 X 8
Tire OD: 655mm/25.8”
Rear: 275/30 -19 X 9.5
Tire OD: 649mm/25.6”
Front ET/Offset: 60?
Rear ET/Offset: 49

One Extreme Example: (Z06 Corvette)
(Requires significant fender flares)

Front Tire: 285X35X19 on 19 X 10” Rim
Tire OD: 26.9 (683mm)
Taller: 1.22" (31mm) 4.8%
Ride Height: +.61" – Have to lower suspension/limit travel to adjust ride height
Rear Tire size: 335X30X19 on 19 X 12” rim
Tire Diameter: 27" (685mm)
Taller: 1.3” (33mm) 5% larger

Joe

 

Hey im look-in to by some new rim for my 04 S type. i found the one that caught my eye buy im not sure if these are going to fit perfectly without have any issues. my main concern that don't have any rubbing issues and also that the brake caliber clears the rims. these are spec20x7.5 Black Ice Mayhem 5x108 5x4.25 +40mm ) can you please help me out ?
20x7 5 Black Ice Mayhem 5x108 5x4 25 40mm Black w Chrome Wheels Rims inch 20" | eBay

 

TIJoe, thanks for pulling this information together on OE wheel (and tire) sizes and specs.

The OE wheels really do have a very high positive offset -- wow. For the OE wheel in 17"x7.5", I am seeing these specs: 7.5" = 190.5 mm; half of that (centerline) is 95.25. Less 60 mm offset means the mounting surface (which is on the inside) is only 35.25 mm (about 1 3/8") from outside edge of rim; 155.25 mm from inside edge of rim.

Taking one aftermarket wheel offered for the S-type, the Coventry wheels, they have either 18" or 19" x 8.5" with 42 mm offset. 8.5" = 215.9 mm; centerline is 108 (rounded) mm; less 42 mm offset has the mounting surface 66 mm from outside edge and 150 mm from inside edge of rim. That means these Coventry wheels sit farther to the outside such that the inside edge of the rim is actually farther out even though the wheel is 1" (25(.4) mm) wider, and the outside edge sticks out 30.75 mm (1.2") farther out than the OE rim. Usually when wheel width is increased some of the extra width extends on the inside edge, with more of the extra width on the outside edge. But for the Coventry wheels, all of the extra width is on the outside side of the wheel, plus the inside is 5 mm farther toward the outside / curb side. That makes me wonder about fitment on these Coventry wheels.

To at least match where the inside edge of the wheel is with the OE wheels (in the 17x7.5 ET60 referenced), a wheel in 8" width would need an offset of +53-54, and an 8.5" wheel would need an offset of +47-48 mm. So, it appears the Coventry wheels (for example) in 8.5" width should have an offset of about 50, not 42.

I saw the pictures of one of the STR owners with Coventry Hornets and there was a problem with the rears, but I am wondering about the fronts, which would be what I am interested in putting on all four wheels. Anyone with Coventry wheels in 8.5" width 42 offset see any problems?

 

My stock tire size is 235/50r17 (26.3")

The big question is, how far can you go without reprogramming the computer? And can the computer be reprogrammed for tire size?
Is it programmed for a 26.3" diameter or 25.7" diameter tire?
How wide can you go on the origional 17X7.5 wheel befor the tires rub?

Options I was looking at are. (Continental ExtremeContact DWS)

235/50r17 (26.3") Stock on my vehicle. +2.3%

235/45r17 (25.3") Lower Profile, should improve performance. -1.6%
May Look too small on the S-Type. Should help both acceleration and conering.

245/45r17 (25.7") Rims are only 7.5" and this may be a tight squeeze.
Narrowest recommended rim, could work well. Should in theory corner and accelerate better than my stock tire. This is the logical solution in my mind.

245/50r17 (26.3") This OD does not seem corrent. +2.3%
Listed Specs look the same as the 235/50?
Logic dictates 26.7" +3.9% but only 1.5% bigger than my stock size.
This would look great in the wheel well, but both conering and acceleration should suffer, maybe.

255/45r17 (26") This should have at least an 8" rim width. +1%
Should fill the wheel wells great, but, Should be on a min of a 8" rim and my stocker is only 7.5". Wheel bulge could be an issue. Could hurt cornering performance because of this. "This is the size I would run if they could fit front and rear." Would fill the wheel wells without lowering.
Not sure they would fit on the front. Could run the Coventry wheels 17X8 but a lot of money in wheels and tires for the value of the vehicle.

 

-- truncated --

My stock size is 235/50-17 also. This is the stock/OE size I am seeing for 17" wheels both in the 2003 and 2005 Jaguar owner's manuals I looked at, and on Tire Rack (for 2005 m.y. and others). At 26.3" they are definitely larger than the other size tires that came on the S-type stock, which are 25.7-25.8" in diameter.

Brian or anyone else -- have you figured out if the computer is programmed specifically for the 26.3" diameter versus the 25.7-8" diameter? Or are our speedometers and odometers and everything else that depends on vehicle speed just off from the rest of the S-types with different OE tires? I guess I'll ask the Jaguar dealer in Salt Lake City when I am up there to get the PAS additive.

Brian, I have been looking at the 245/45-17 size in a higher performance tire, too, since looking into it following your posts. That would certainly be a less expensive option (not requiring new wheels/rims -- saves $1,000+ because the 17" tires are cheaper, too) and may be best for acceleration and fuel economy since there would be less inertia in the wheel (not an engineer, don't know if that's the right term) -- the same size OD of 25.7" on a 17" rim versus 18" rim will spin up with less energy in 17" than 18" rim size, since the extra 1/2" of sidewall with air in between has less mass than the additional aluminum alloy of a 18" wheel versus a 17" wheel. I see in the 2005 manual/handbook that they list weights for options, and the 17" Aurora wheels on my VDP are at a "0" while weight is added with every other wheel option except one (Juno style). Here are the added weights in pounds for a set of 4 optional wheels (not counting options for the spare listed separately): Triton: 7.9; Valencia: 3.4; Melbourne: 23.7 (!); Barcelona: 7.1; Monaco: 15.9; Indianapolis: 24.3 (!). I don't know the weight of the Juno and Aurora wheels that have a zero added weight from the base curb/kerb weight. The Coventry Hornets look fairly heavy - they have a big/thick rim part of the wheel, and they are 1" wider.

FYI, Tire Rack has a special on the Continental ExtremeContact DW (not DWS) in 245/45-17: $115 (plus shipping). These Conti Extreme DWs are highly recommended by some of the STR owners on the forum, and I saw near rave reviews of this tire on Tire Rack by Jag owners (at least one of whom I think I recognize from this forum). I will be getting dedicated winter tires this November or thereabouts, so I would be using a summer tire, but my Michelin Pilot HXs should last till then and I am still looking at going with the Coventry Hornets in 18x8.5 with 245/40-18, so I'll wait till a year from now to pull the trigger on a set of summer rubber. I'll decide then whether to stay with the stock 17" wheels or go with a more "stanced" (just discovered that word here) setup with the Coventrys (1" wider and less positive offset -- rim edge pushed out 1.2" from the stock) and 40-profile tires.

Brian, you wondered about maximum tire width on the S-type. I think I read months ago that 245 was the widest tire that could be fitted in the front without rubbing, though that would seem to depend on wheel offset, and the reported rubbing may have been with wheels and tires specked for the X350 XJ or XF, which use larger diameter tires. Anyway, 245 width in a grippy tire should be plenty of width, especially in a lower profile (wider tread width)

 

Aren't there settings in IDS/SDD?

 

Are you sure about those rear offsets for the STR? I was sure they were 60/60 front and rear.

 

I would assume the computer is programmed for the tire size of 26.3 (probably 26.5) and not 25.7. The liability if the Auto Manufacturer having you going faster than the speedometer is much higher than going slower. The 2.3% difference is not a whole lot, but a minimal margin for safety.

I am still a little confused why the Continental EC DWS 235/50 and 245/50 both list the same outside diameter of 26.3

So I contacted TireRack:
Tanner: The 235/50R17 is 26.3" tall and will work on a 7.5" rim width. The 245/50R17 is also 26.3" tall and will also work on the 7.5" rim width.
Tanner: The section width on the 245/50R17 is 9.7" and for the 235/50R17, also 9.7.
Tanner: The tread width he 235/50R17 is 9.25" and 9.64" for the 245/50R17.
Tanner: The 245/50R17 weighs 25 pounds and the 235/50R17 weighs 24 pounds.

 

Also, the 245/45r17 on 8" is 25.7" tall, 9.6 Section width and 9.1 tread width.
Seems like all the tires are different designs.

Given the examples listed above, and assuming they are correct....

The 245/50r17 on 7.5" rim in this "specific" tire, does not look like a bad option for someone looking at keeping the stock ride height suspension and stock tire diameter of 26.3". Keep the wheel wells looking full and having a 9.64" tread width on a 9.7" sidewall. Now that is a square profile tire......

 

So will the staggered zeus rims 18x8 front 18x9.5 in rear fit on a non STR?

 

Probably depends most on offsets. I don't imagine the fender well space is much different between the r's and non r's. And thoes are the same as the stock r rims. Also I'm running 265/40 on front and 285/40 on rear and I have no tc issues. Didn't have problems with 255/40 on front either. I did have problems with 245/45 fronts and 265/35 rears so I think as long as the front to rear ratio is close it's ok

 

Were you using the stock 18x8 wheels with the 265/40 and 255/40 front setup?

 

Yes I am. The 265/40s are michelins. They are made out of more poly cords and less steel cords which make them more flexible. I tried the 265/35s on front (forgot the brand) and they didn't work well. Kinda pulled the tread down onto the sidewall some which is why I went to 265/40s and also michelins Cuz the sidewall flexes more and they appear to fit very well. Haven't had them for too long so don't know for sure but time will tell. Picture is the 265/40s

 

Hi so I NEED TO ask,
My brakes brake beautifully, I drove it in very heavy n light rain, the light rain made me jump n slide all over the road, I usually apply my brake slowly n ease into a stop n its still doing this during rain, after rain fine!
This is my first car (lol I love it) I have a 3 year old daughter, I need to make it as safe as possible so im trying to fix this issue.

Someone told me brakes someone else said tred on tyres is bad another said I have crappy Firestone tyres ANY INSIGHT OR HELP?

THANK U U GUYS HAVE RIGHT SPOT ON WITH MY OTHER ISSUE (GEARSHIFT CAM) N V8 HAS BEEN GREAT BEARING WITH ME SO TY U GUYS IN ADVANCE!

 

It has ABS (& TC). Go somewhere safe but slippy and brake hard. Don't let up. You should feel a rapid pulsing as the ABS cuts in. If you don't then you didn't brake hard enough. Emphasis: safe. Sub-emphasis: slippy (gravel will do, doesn't have to be water). Don't experiment in traffic!

 

Has anyone tried mounting 19x8.5 27mm fronts and 20x10.5 40mm rears? I drive a 2000 S-type 4.0L High end. Thanks in advance.

 

Maybe not - but have you changed the chain tensioners and related plastic parts?

 

Got hurt at work hence not a chance to get under the hood yet. On a better note, she's driving good. Thanks for asking!

 

Did we ever determine the facts on STR wheel offset? Is it 60/60 or 60/49? I could swear the factory wheels were staggered.

 

I think they're ET 60 and yes staggered.