You just purchased new NGK spark plugs for your 99 prism you know the gap is 043 however the plugs were preset at the factory and using pair of calipers the gap is 036 Should you expand the gap or ins?
Set the plug gap according to your owner's manual specs. Although the gap is set at the factory, it may close slightly due to being bounced around during shipping. Also this particular type plug may be used in many different applications and the .036 setting may just be a compromise of all applications these plugs fit. Set the plugs at .043 if that is what your owners manual says.