In this case it's a 2005 engine so the problem with early 1.8T intercoolers probably does not apply.
The ECU may only be calibrated for 95 so putting in 98 would not cause the ignition to be advance any further.
I doubt anyone could tell the difference between 95 and 98 in a blind test in this particular car.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.