The Alfa Romeo 105 Series Spiders (1970-1993) were available with two styles of OEM alloy wheels. One style is typically referred to as the Turbina, while while the other is referred to as the Daytona.
The Turbina wheels have manny small radial fins, while the Daytona wheels have five heavy radial spokes. The Daytonas are wider and heavier than the Turbinas. The Turbina wheels were a popular option on European cars, while Daytonas were popular in the American market.
Originally, the wheels were supplied to the factory by two Italian companies: Campagnolo and Cromodora. Wheels from the two manufacturers differed slightly in appearance and manufacturing techniques.
The Cromodora Turbinas are almost visually identical to the Campagnolo version – indeed some cars are reported to be running a mixed set of rims with the owners none the wiser – but a close inspection should reveal that the Campagnolo wheels have square-edged radial fins, while those of the Cromodora are a bit more rounded.
Cromodora also produced a later version of a Turbina style of wheel, which was fitted to Alfa Romeo 116 Series Alfettas. These have a different stud PCD as well as different offset and so can’t be used on 105 Series Alfas. The later Alfetta wheels are easily recognised as they have openings between all the radial ribs on the face of the wheels, while the Turbinas for 105 Series cars have an opening every second rib.
While there are only small visual differences between 105 Series Campagnolo and Cromodora Turbinas, the technical differences are somewhat more significant. The Campagnolo Turbinas, originating from a small-volume manufacturer, are aluminium sand castings, weighing around 5.785kg each. A careful sand castings can be very good, but as a generalisation, they tend to exhibit a bit more variability between castings and the surface can be a bit rough – consequently they are potentially more time consuming to finish and balance.
The Cromodora Turbinas, from a much larger manufacturer, are typically injection moulded die-castings with high magnesium content. The Cromodora are slightly lighter (5.725kg) and more finely finished, which means they are also easier to balance and keep clean on the car.
By comparison, the standard steel rim fitted to 105 Series cars weighs in at ???kg.
The Cromodora Alfetta Turbinas, with less metal between the ribs, are lighter again than the 105 Series Turbinas, weighing in around 5.555kg each.
The Daytona style wheels, from both manufacturers, are 6” wide compared to the 5.5” of the Turbinas and are appreciably heavier.