I was wondering what would happen if I were to put 5W-40 oil in a 2013 1.2TSI engine. I'm aware that 5W-30 is the recommended type but I have a 5L bottle of 5W-40 left from my old car. So I am just wondering if it would be okay to put this in instead to save myself some money.

Yes, I use royal purple 5w40 in my 1.2 tsi fabia previously motul x cess gen 2 5w40.

Look for vw 502.00 for fixed service or vw 504.00 spec for variable service

^^^ Exactly right. 5w 30 FS III is Long Life oil for Fixed or Variable Servicing. VW 504 00 / 507 00 with TSI,s. & 5w 40 FS iVW 502 00 s for fixed Servicing with TSI,s, (5w 40 FS not for TDI,s)... Only mix if a little. But using 5w 40 FS (non Long life) is Simply Clever IMO.

Edited 16 March16 Mar by Evolution13

Thank you both