I've got a 2018 GTI SE 90 I bought that has 30 hours on it. Took it out for the first time yesterday and I know it'll be slower given it's the 90hp engine, but I'd expect it to be able to get over 30mph. It tops out around 29mph and maybe would hit 30 once or twice. Engine seems fine, it's running well and revving to 8K rpm. It does feel a bit sluggish off the start. Based on searching maybe the wear ring is bad?