Hello
Hopefully someone can help me with this question
I have just purchased a 2004 s type 4.2 v8 for my wife
But I do not like the factory wheels
They are 17 inch with a et 60
I am looking at some 18 inch
But my concern is the off set which is
Et 50
So I do not know if they will fit
The guy who has them brought them at a auction and they are still in there boxes
He got them for a s type 3.0
Also what size tire could I fit
I was thinking about a 245 /45/18
But not sure
Thanks
Darrol

 

the early S Type-R comes out on staggered 18'' wheels .
front are 8'' with off set of 60
rear's are 9.5'' with offset of 60

there is a spare 25mm at the front and 10mm at the rear on mine .
so a square set up of 18x8'' at ET50 will work .

 

Depending on where the car is you may need (will need in some places) to tell your insurer.

There will be other implications of changing the ET but I'm unsure of all of them. (suspension wear? changed handling?)

Going to 18" will make the ride harsher of course.

 

Thanks for the help
Now I need to work out what size tire will fit on the new 18s
At the moment I have 235/50/17

 

ET reduction of 10 mm will make the wheels stick out 10 mm further. It will probably not catch anywhere.

The downsides will be heavier steering, more tramlining, etc. plus higher loads on the bearings, etc. Changing the offset changes the scrub angle and you can feel it. The further away from standard you go, the less willing the steering is to do exactly as you ask (heavier, slower, less delicate). There are good reasons why the manufacturer chose certain settings.

If you don't mind the drawbacks, the correct tyre size is 245/40-18.

 

Hi
ET reduction will bring the wheels in, not out 10mm
cheers
Joe

 

good spotting joe ! Quite true .
then in this case some 20mm hubcentrick spacers should fix all .
also for 8" x 18" rims I'd go with 235/40-18 or 245/40-18

 

Try again Joe!

ET is the back spacing. German: Einpresstiefe. So the distance from the mounting face to the inner rim of the wheel. The bigger the ET, the further in the wheel sits (unless it hits something first).

S-Types with ET of around 60 mm sit a long way in. Loads of aftermarket wheels fit but have a lower ET and stick out. Made the same mistake with aftermarket wheels for our Impreza 2 decades ago. It never felt right on the wheels with the lower ET. Wider track but ruined the steering feel. Since then I try and stick with original wheels or aftermarket with very similar ET.

 

The wheels stick out more with a reduced positive offset.

 

hi
the STR wheels that come with my Jaguar STR are 60mm positive offset
so fitting et50, 50 positive offset would bring the wheel away from the arch
ET is not back spacing, just look at the wheel
the wheel is about 240mm wide, 9 1/2 inches, the centre line is about 120mm, the offset, ET, is 60mm, the back spacing is about 180mm, no where near 60mm
cheers
Joe



https://www.tyresizecalculator.com/wheels/wheel-offset

 

Sorry, ET is not back spacing, agreed but your geometry is wrong. This guy has explained it correctly (as has Robinus):

https://www.moderntiredealer.com/art...o-wheel-offset

Especially this bit:

This is why that ideally, you don’t want the new offset to be more than 5 millimeters away from the old offset in either direction. However, this isn’t always possible. What you do need to keep in mind is that more negative offset, i.e., an offset that is less than the original, will push the wheel out farther from the wheel well. Usually, this will not cause a problem, although it might result in a pretty funky look.

In contrast, too much positive offset is a danger, as it will push the wheel farther in toward the suspension. Here’s an extreme example: If you have to go from a 45 mm offset to a 20 mm, the wheels will protrude from the sides of the car. But going from a 20 mm to a 45 mm offset not only may destroy the tires, but also has the potential of affecting vehicle control and injuring the customer — not an optimal customer service outcome!

In your positive ET 20 picture, increase the 20 to 60 and the blue line moves outwards 40 mm. The hub on the car remains in the same place so more of the wheel barrel goes under the wheel arch.

In short, reduce the ET or offset and the wheel moves outwards.

The suggestion above of an ET50 wheel plus 20 mm spacers would bring the wheel 30 mm further out plus half whatever the wheel width increase is - it would be a disaster.

 

Mmmm, too bad that Jaguar had to use such an extreme offset. I have found some nice aftermarket wheels, not real showy or flashy, but the offset is 48.

 

Yes! I was in the same boat a few years back when I fancied putting bigger, heavier wheels on mine. None of the decent aftermarket wheels had such high ET values. I then came across a set of new Jaguar 18x8" Melbourne wheels at about the price of aftermarket ones. They look good and fit correctly. However, the car actually still feels sweeter on the original 16" ones. These days, new ones at sensible prices are hard to find.

 

I'm not really interested in +1 or +2ing my car, I like the 17" diameter, it makes a nice proportion of rubber and wheel. I just wanted to find something a little less "factory" in look.