Please no wife tales on this one. Why are some UK people advising exhaust valves to 0,25 mm. I do know why but need to be convinced of the benefit. I have service 1000’s of A-models and ALWAYS adjusted the exhaust valve at 0,20 mm just like Citroën recommend. Never had any problems even in extreme hot condition in the Australian out back, driving for weeks, no worries.

I know its done to allow more heat to move away from the valves. No worries when racing but why on earth set the valves to 0.25 on standard street cars. They do not over heat if the engine is serviced correctly. If/when driving around the UK winter with this setting, the engine oil never get to correct working temp. not good for engine. Even with 0.20 mm its struggeling to warm up, hence the plastic cover in front of the fan.