Hi BSA,
Those 4-349 Scorcher tyres are HUGE! 
Wider = more grip / 16 inch but larger than 18" - soaks up more road bumps.
What is the PSI for them? I can’t tell.
Do they have more rolling resistance? Does it take more effort to pedal to maintain speeds?
The Efneo prototype honestly looks TOO GOOD! If they are selling I’ll consider one for sure ! Better top speed than EVO - so YES PLEASE! 