Valve Lash Clearance

[aamiraijaz]

I have a Suzuki Baleno 1.3 SOHC 16v car. I want to know about valve clearance of intake and exhaust. The factory setting for cold engine is 0.007-0.009in on intake and 0.011-0.013in on exhaust. My 1st question is why the mechanics are going for 0.08 (intake) and 0.10 (exhaust). The 2nd question is why they are setting the valves at a difference 0 0.2 between intake and exhaust when the factory says a difference of 0.4 Also i want to know which would be the best setting for greater fuel economy?

Thanks.