I have 20'' factory rims they are they grey one from 2010


they are 20'' by 8'' offsets +19
http://i.ebayimg.com/images/a/(KGrHq...Q~~/s-l300.jpg


factory sport rims are 9'' wide same offsets
http://pictures.topspeed.com/IMG/cro...-10_600x0w.jpg


why do they give the effect of having a different offset they seems to stick out more ??

 

offset is measured from the center of the rim - so the center of the 8" rim and the center of the 9" rim would be in the same spot if they have the same offset. Wider rim sticks out more

 

https://www.customwheeloffset.com/of...ng-what-is-it/

Basically it is because what sawtewth said, it is because the wheel is wider it will stick out more.