One article why integrated exhaust manifold is a good thing to have. And Citigo have it already. 

 

http://jalopnik.com/automakers-are-changing-to-integrated-exhaust-manifolds-1796305029?utm_source=facebook&utm_medium=partner&utm_campaign=drivetribe

Very short primary exhaust runners are usually very bad for low end torque, which is a particular problem when you don't have forced induction to compensate. I don't think the CHY engine has variable valve timing either so can't help wondering if we are losing a useful chunk of torque in the quest for lower emissions.

 

Also 

 

 

Edited 25 June, 20178 yr by ronime

I think there is variable valve timing. At least it pull nicely at low rpm. For me it's important that engine warm up quickly. Because it's quite cold up here at winter.