Turns out like the 16inch stock FD rims, the 17 inch "99 spec" rims also have 2 castings.
One being 2 lbs lighter than the other per rim

Have anyone had experiences with the lighter rims more prone to cracking or damage?

 

The 17s will go square if you make a habit of driving over objects or into holes.

Haven't heard of different castings, wheel part numbers for version V and VI don't seem to have altered either with no A or B suffixes. 2lb difference would be over 10% weight change too, which seems a bit unlikely to me. The BBS 17s are about that much heavier however - and there were several changes there depending on date of manufacture and paint for different models.

 

Here are the 2 castings

 

What, if any casting numbers on the rims?

Have some sets that have that ridge in the barrel from memory, but they might just be the rears, have to check the fronts.

 

No special market on the rims that I can see.

 

whats the weight on yours ? mine weigh 8.2kg and 8.6 kg
some guy was saying that his were close to 10kg or so

 

Lighter set is 6.2kg / 7.1kg
Heavier set is 7.2kg / 8.0kg

All from my Ikea bathroom scale (don't know how accurate it is)

I did find a "R" marking on the spokes of the lighter set. Maybe it's RS vs RZ rims?

 

Rz were BBS not the cast mazda versions.

The "channels" from the spokes running into the mounting face, I don't recall seeing those before now.
Edit: do think the ikea scale is off, around 8 and 8.5kg on corner weight scales ages ago is my memory too

 

Which casting does your wheel have? Top or bottom from my post up top?

 

I think it's the same detail in one respect as the first one, with the enclosing ring around the lug holes. As said, fairly sure it has the barrel, same as the second with the reinforcing though.

I'd have to double check, last use was just dyno wheels a couple of years back.

 

Ok, top picture is the heavier set, bottom picture is the lighter set.

 

Looks like I have the lighter set...I'll try to get weights when I remove the tires.

 

These rims were offered from '95 onwards on the RS and other models that needed the extra clearance for the larger brake calipers. There are no part number revisions, maybe it changed the same time as they updated the centre caps from Efini to Mazda badges for the S8?

 

I think you're correct!

Finally had a look at the ones here today and there's both varieties. It's a bit of a gamble with the Japanese fad of putting efini bits and pieces on everything 15 or so years ago, but the mazda centre caps seem to belong on the long channel variety and the efini on the full contact mounting face type.......if the tyre fitters haven't done the old switchero at some stage.

 

Any updates to confirm which cast of the 99 spec wheels is lighter? Considering looking for a set of the light weight ones. Thx!