Lump of cast iron or not. The Tuna dose handle well rain or shine. It's not a sports car it's an MPV. My family were here for a holiday some time ago and I had to cart around 10 of us. Ok it was a bit of a push room wise, but it got us to where we wanted to go without any problems. So, they will do the job they were designed for. Oh, just one small point my lump is now 6 years old, and I have never had a problem other than changing the battery and general service.