Quote: Randa france wrote in post #1
Traditionally, when you used to compare cars with steel wheels to their rather more flashy sisters who sported alloys, the alloy wheels were one size bigger, ie. a 15" Steel wheeled Galaxy and a 16" Alloy wheeled Galaxy.
Does the same apply to Eriba Caravans or are they like sized and take the same size tyre?
The reason for the increased diameter of alloys is usually, but not always, cosmetic. The downside of vanity is that in order to retain the same rolling radius (and therefore avoid buggering up the gearing and the speedometer reading) the tyres fitted to the alloys are shorter (and stiffer) in the sidewall, and the ride suffers as a consequence.
The manufacturer would say that the stiffer sidewall improves turn-in and sharpens up the handling, and is therefore a Good Thing.
A crashy ride and loose dentures might suggest otherwise.
When I got the Troll's alloys, I just refitted the tyres from the steel wheels. The alloys are half a section wider than the steelies - 6J rather than 5.5J - but the tyres can accommodate that easily. The diameter is the same, as Alan said.