Yeah this is covering old ground from this very thread. ADR 25a is correct.
For some reason I thought this was another thread that had started (again) on the same topic.
The problem is 30-40 years after release people have changed or purchased new steering wheels so you see 3mm wheels on older cars often. Doesn't help when the owner tells you it's factory original when clearly it's not! Sean covered it well back on page 3.
Bookmarks