XJS ( X27 ) 1975 - 1996 3.6 4.0 5.3 6.0

C4 Wheels

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Old Apr 21, 2022 | 02:14 PM
  #1  
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Default C4 Wheels

As much as I like the old "starfish" style wheels, you just can't fit any meat on them. Not a big fan of the later XJS wheels that were only slightly wider.

Turns out that from 1984-1987, the standard Corvette came with 16x8.5 wheels and +32 offset. Bolt pattern matches ours: 5x120.65. That width & offset should work as-is or with very little modification based on this past thread: https://www.jaguarforums.com/forum/x...-wheels-65576/

I think the fronts would need a minor spacer to not encounter the front suspension, but I don't think any other mods would be necessary.

Now for the important part (pardon my sloppy Photoshop skills):



Was never a huge C4 guy, but I think these wheels match the XJS styling nicely. Just my opinion of course, but really wanted to hear if anyone had actually done this.

You can get a decent set of C4 wheels for less than $300. Not too heavy either; about 20 lbs each. Standard tire size is 255/50.
 
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Old Apr 21, 2022 | 03:53 PM
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I don't know about fitment but I do agree that they look pretty good on the car.
It would look even better if they were 16".
 
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Old Apr 21, 2022 | 04:11 PM
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Some pix in this old thread.
https://www.jaguarforums.com/forum/x...ld-ride-38914/
 
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Old Apr 21, 2022 | 05:32 PM
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X300 and X308 wheels fit as well, plenty of choice in larger rims there.
 
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Old Apr 21, 2022 | 05:44 PM
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Originally Posted by petemohr
I don't know about fitment but I do agree that they look pretty good on the car.
It would look even better if they were 16".
Do you mean 17? These are 16”. The C4 got 17’s (in a different style) starting in 88.
 
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Old Apr 21, 2022 | 05:45 PM
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Originally Posted by petemohr
I don't know about fitment but I do agree that they look pretty good on the car.
It would look even better if they were 16".
What concerns over fitment would you have?
 
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Old May 1, 2022 | 05:34 PM
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https://tiresize.com/wheel-offset-calculator/

Use this to see the difference.

 
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Old May 1, 2022 | 05:35 PM
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https://tiresize.com/wheel-offset-calculator/

Use this to see the difference.


most chevy wheels from 80s to early 90s will fit. Its the hub you need to get correct. The jags have a huge hub. You can get hub centric spacers to a make them work. About 200 usd.
 
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Old May 1, 2022 | 08:26 PM
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Not worth using C4 wheels because the availability of reasonably priced street tires is poor.
 
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Old May 2, 2022 | 09:43 PM
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The bore in the Corvette wheels is too SMALL, and would need to be opened up to 73.9mm. Most machine shops can handle this with no problem. Hub-centric spacers would only be used if the wheels in question had a LARGER hub opening than our cars, but that's not the case.

See this link for a pic of these wheels on a '76: Custom 1976 Jaguar XJ-S Coupe

I'm not a fan of the 944-style rear wheel arches and spacers pushing the rear wheels out.
 
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Old May 3, 2022 | 12:32 PM
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Originally Posted by Spyhunter2k
The bore in the Corvette wheels is too SMALL, and would need to be opened up to 73.9mm. Most machine shops can handle this with no problem. Hub-centric spacers would only be used if the wheels in question had a LARGER hub opening than our cars, but that's not the case.

See this link for a pic of these wheels on a '76: Custom 1976 Jaguar XJ-S Coupe

I'm not a fan of the 944-style rear wheel arches and spacers pushing the rear wheels out.
Ah the famous Spyhunter! I've been using your "Ideal Offset" thread as my main reference during my wheel search. I agree with your take on the C4 wheels in that particular case, and to be honest, I'm leaning away from them now. I really like the original starfish and lattice XJS wheels - they're just too darn narrow!

Maybe you could check my math on another alternative. The 1982-1992 Firebird wheels had a classic lattice design that I really like. The 87-92 range looked the same but instead of 15x7, they were 16x8.

The fronts came with zero offset (obviously way too little for front or rear on an XJS), but the rears came with 16 mm offset. That's pushing it, but based on your thread, I think a little fender rolling and pulling would clear these just fine, even with a meaty 255/50 tire fitted (though in the front I'd step it down to 225 or 235). Center bore is 70.3, so that would need to be machined. Not sure how much machining is too much.
 
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Old May 3, 2022 | 05:04 PM
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I actually have a set of these myself as a back up option—4 1987 model year "rears" with 16mm offset. They were released as GM RPO code PW7 in the middle of the 1986 model year, and were made in Japan as a lightweight alternative wheel to the then-current Trans Am wheel so that Trans Ams with lots of options (TPI engine + glass T-tops + A/C, etc.) wouldn't exceed a certain weight targets associated with CAFE regulations. Some Trans Ams received this wheel, but since all GTAs did they are usually referred to simply as "GTA wheels."

There are two generations of these wheels. In 1986 and 1987, they have no "dimples" on the outside edges, and are actually two-piece (welded inside) wheels with cast centers. Between 88–92 they transitioned to cast one-piece wheels—still made in Japan—with "dimples" around the outside. Cast reproductions are available of the one-piece 88–92 style, made in Taiwan I believe, but in black or gold only. By special request, you can get all four as 16mm-offset "rears."

Once the bores are opened up to 73.9, they should work fine if using 225-width tires. Or if you wanted a setup similar to the staggered widths of the TWR/JaguarSport cars, you could also have the rears sent to Weldcraft in Michigan for 1" to be added to the insides, resulting in a 29mm offset, in which case a 255-width tire could be mounted to the rears with no fender pulling (since the addition of material to the inside of the rears would result in the rear tire being shifted positionally inwards). I would advise against using a 255-width tire on a stock 8" rim with 16mm offset, for two reasons: 1) 245 is pretty much the max width for an 8" tire, handling wise. 255 will fit, but will be really bulgy and handling will noticeably suffer. 2) The fenders are only known to allow a 1/2" pull to the outside. A bit more would be necessary for a 255-width tire on a 16mm offset wheel. And the point of impact at the rear even when you pull the fender outwards is the inner fender liner. So I would go no higher than 245 on the rear with the stock 16mm offset of these wheels, which would need a pull that doesn't exceed the 1/2" amount known to be possible.

There are two best options for acquiring these wheels: find two sets of the early 2-piece '86-'87 wheels so that you can harvest four 16mm-offset "rears" that are worth the investment to restore (what I did), or buy four 16mm "rear" repros that are made in Taiwan, but of generally good quality and come looking brand new. Used '88–'92 wheels should only be considered if in perfect condition without need for expensive restoration. Be careful that you are not buying Buick wheels of the same design meant for Grand Nationals or GNX cars. The unique lower offsets used on these would result in the wheels sticking WAY out.

Hope this helps.
 

Last edited by Spyhunter2k; May 3, 2022 at 05:08 PM.
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Old May 3, 2022 | 10:42 PM
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Originally Posted by Spyhunter2k
I actually have a set of these myself as a back up option—4 1987 model year "rears" with 16mm offset. They were released as GM RPO code PW7 in the middle of the 1986 model year, and were made in Japan as a lightweight alternative wheel to the then-current Trans Am wheel so that Trans Ams with lots of options (TPI engine + glass T-tops + A/C, etc.) wouldn't exceed a certain weight targets associated with CAFE regulations. Some Trans Ams received this wheel, but since all GTAs did they are usually referred to simply as "GTA wheels."

There are two generations of these wheels. In 1986 and 1987, they have no "dimples" on the outside edges, and are actually two-piece (welded inside) wheels with cast centers. Between 88–92 they transitioned to cast one-piece wheels—still made in Japan—with "dimples" around the outside. Cast reproductions are available of the one-piece 88–92 style, made in Taiwan I believe, but in black or gold only. By special request, you can get all four as 16mm-offset "rears."

Once the bores are opened up to 73.9, they should work fine if using 225-width tires. Or if you wanted a setup similar to the staggered widths of the TWR/JaguarSport cars, you could also have the rears sent to Weldcraft in Michigan for 1" to be added to the insides, resulting in a 29mm offset, in which case a 255-width tire could be mounted to the rears with no fender pulling (since the addition of material to the inside of the rears would result in the rear tire being shifted positionally inwards). I would advise against using a 255-width tire on a stock 8" rim with 16mm offset, for two reasons: 1) 245 is pretty much the max width for an 8" tire, handling wise. 255 will fit, but will be really bulgy and handling will noticeably suffer. 2) The fenders are only known to allow a 1/2" pull to the outside. A bit more would be necessary for a 255-width tire on a 16mm offset wheel. And the point of impact at the rear even when you pull the fender outwards is the inner fender liner. So I would go no higher than 245 on the rear with the stock 16mm offset of these wheels, which would need a pull that doesn't exceed the 1/2" amount known to be possible.

There are two best options for acquiring these wheels: find two sets of the early 2-piece '86-'87 wheels so that you can harvest four 16mm-offset "rears" that are worth the investment to restore (what I did), or buy four 16mm "rear" repros that are made in Taiwan, but of generally good quality and come looking brand new. Used '88–'92 wheels should only be considered if in perfect condition without need for expensive restoration. Be careful that you are not buying Buick wheels of the same design meant for Grand Nationals or GNX cars. The unique lower offsets used on these would result in the wheels sticking WAY out.

Hope this helps.
Very informative response, thanks! That definitely helps - any idea how much the 1" add-on from Weldcraft might run? Never considered that option.
 
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Old May 11, 2022 | 09:01 PM
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Originally Posted by MrAndersonGCC
Very informative response, thanks! That definitely helps - any idea how much the 1" add-on from Weldcraft might run? Never considered that option.
I think it's about $200/wheel, but you'd have to check with them to be sure.
 
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Old Nov 25, 2023 | 08:33 PM
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Originally Posted by Spyhunter2k;[url=tel:2521614
2521614]I actually have a set of these myself as a back up option—4 1987 model year "rears" with 16mm offset. They were released as GM RPO code PW7 in the middle of the 1986 model year, and were made in Japan as a lightweight alternative wheel to the then-current Trans Am wheel so that Trans Ams with lots of options (TPI engine + glass T-tops + A/C, etc.) wouldn't exceed a certain weight targets associated with CAFE regulations. Some Trans Ams received this wheel, but since all GTAs did they are usually referred to simply as "GTA wheels."

There are two generations of these wheels. In 1986 and 1987, they have no "dimples" on the outside edges, and are actually two-piece (welded inside) wheels with cast centers. Between 88–92 they transitioned to cast one-piece wheels—still made in Japan—with "dimples" around the outside. Cast reproductions are available of the one-piece 88–92 style, made in Taiwan I believe, but in black or gold only. By special request, you can get all four as 16mm-offset "rears."

Once the bores are opened up to 73.9, they should work fine if using 225-width tires. Or if you wanted a setup similar to the staggered widths of the TWR/JaguarSport cars, you could also have the rears sent to Weldcraft in Michigan for 1" to be added to the insides, resulting in a 29mm offset, in which case a 255-width tire could be mounted to the rears with no fender pulling (since the addition of material to the inside of the rears would result in the rear tire being shifted positionally inwards). I would advise against using a 255-width tire on a stock 8" rim with 16mm offset, for two reasons: 1) 245 is pretty much the max width for an 8" tire, handling wise. 255 will fit, but will be really bulgy and handling will noticeably suffer. 2) The fenders are only known to allow a 1/2" pull to the outside. A bit more would be necessary for a 255-width tire on a 16mm offset wheel. And the point of impact at the rear even when you pull the fender outwards is the inner fender liner. So I would go no higher than 245 on the rear with the stock 16mm offset of these wheels, which would need a pull that doesn't exceed the 1/2" amount known to be possible.

There are two best options for acquiring these wheels: find two sets of the early 2-piece '86-'87 wheels so that you can harvest four 16mm-offset "rears" that are worth the investment to restore (what I did), or buy four 16mm "rear" repros that are made in Taiwan, but of generally good quality and come looking brand new. Used '88–'92 wheels should only be considered if in perfect condition without need for expensive restoration. Be careful that you are not buying Buick wheels of the same design meant for Grand Nationals or GNX cars. The unique lower offsets used on these would result in the wheels sticking WAY out.

Hope this helps.
Reviving this thread with a question for you. Would a 245 tire fit in the rear with 16x8 with 16 mm of offset?
 
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Old Nov 26, 2023 | 04:10 PM
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Here's my take on this. Not all 245 tires are created equal as some have wider tread widths than others although most have the 10" wide sectional. I have the BFG G Force Comp 2 A/S 245/50zr16 and it's a massive tire with like a 9.5" contact patch. They are mounted on the 7j x 16 forged lattice wheels with the 28.5 mm offset. At the 16mm offset (1/2" approx.) less would only allow 3/4" compression of the rear before the lip hits the tire. That's free height and I can easily push the bumper down 3/4". With me in it, some groceries and the 8" wheel I think it would make contact. My 1989 sits low so a higher ride height would possibly add more clearance.
 
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Old Nov 26, 2023 | 07:12 PM
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Originally Posted by lt1-xjs;[url=tel:2698335
2698335]Here's my take on this. Not all 245 tires are created equal as some have wider tread widths than others although most have the 10" wide sectional. I have the BFG G Force Comp 2 A/S 245/50zr16 and it's a massive tire with like a 9.5" contact patch. They are mounted on the 7j x 16 forged lattice wheels with the 28.5 mm offset. At the 16mm offset (1/2" approx.) less would only allow 3/4" compression of the rear before the lip hits the tire. That's free height and I can easily push the bumper down 3/4". With me in it, some groceries and the 8" wheel I think it would make contact. My 1989 sits low so a higher ride height would possibly add more clearance.
Do you have pics? Would love to see what the 245’s look like, especially from the rear.

I’m also interested to see the 16” lattice wheels. I read about those existing on the facelift models but I can’t find any for the life of me.
 

Last edited by MrAndersonGCC; Nov 26, 2023 at 07:15 PM.
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Old Nov 26, 2023 | 09:32 PM
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245/45R17 on mine.

17x8 et28

no rubbing

Had same tires on a set of 17x8 et20 and it was really close on rear fender lips. Actually rubbed once on a big dip at highway speed.
 
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Old Nov 27, 2023 | 02:49 PM
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Originally Posted by MrAndersonGCC
Do you have pics? Would love to see what the 245’s look like, especially from the rear.

I’m also interested to see the 16” lattice wheels. I read about those existing on the facelift models but I can’t find any for the life of me.
I don't have a direct rear shot but I took these a few months back. The wheels were put on 20 years ago. I did pick up one more wheel 3 years ago off ebay and I think it was the last one in the country.



 
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Old Nov 27, 2023 | 03:29 PM
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Beautiful!

I'm leaning in another direction now: simply having the starfish wheels refinished (perhaps even chrome plated) and sending the rears to Weldcraft to add 1.5 inches to the rears, inwards, and then using a small spacer to bring them outwards a touch. I just can't find much in a 16" wheel that fits and suits the XJS. 17 is too big for me taste.
 
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