Strange this, another gripe from customers complaining about Ryanair policy, but the thing is ALL aero company has a similar policy so i dont see the issue other than scaremongering.
According to the captain of Ryanair's base at Stansted number two on the management team - Shane McKeon: "The most unreasonable excuse of all is that they like to land with three tonnes of fuel” .
Consider it, if you loaded your car with 4 adults, their baggage then put a trailer or caravan on the back, what would the fuel consumption be? It is the same with an aeroplane fuel economy drops with ecessive weight, so that why your luggage is weighed. Also if the aeroplane is carrying excessive weight your luggage capacity is reduced, and more fuel used, so the normal amount carried is calculated for the total needed for the trip, with a small margin extra added on.
Woodbug, you quote that, "after running low on fuel on July 26th The flights were diverted to the Valencia airport after thunderstorms in Madrid and all 3 aircraft landed safely." Would this be due more to the bad weather causing an airborne delay for all three due to exceptional circumstances rather than any fault on Ryanairs part? I would consider thunderstorms to be rather out of the norm.
You would get the same from any air company, as they dont want to haul excess weight, and have systems in place to compensate for any problem, this is why the flights were diverted to Valencia due to the weather.