PETRONAS Syntium 3000 AV 5W-40 vs PETRONAS Syntium 3000 E 5W-40

[inquirer]

The officially suggested oil for the Fiat 1.4L T-Jet 120PS LPG engine is the Selenia MULTIPOWER GAS 5W-40.

Since I don't plan to purchase the Selenia brand for pricing reasons, which of the PETRONAS Syntium 3000 AV 5W-40 and PETRONAS Syntium 3000 E 5W-40 would better suit the Tipo's engine?

 

[inquirer]

The car's manual calls for an ACEA C3 / API SN oil.
Syntium 3000 AV is an API SP ACEA C3 oil, while Syntium 3000 E is an API SN/CF ACEA A3/B4 oil.

The manual calls for FCA 9.55535-T2 specification for LPG engines, but both Petronas oils cover FCA 955535-S2 instead. Only the Selenia fulfills the required one.

Syntium 3000 E has a higher TBN of 2.54 mgKOH/g compared to Syntium 3000 AV.

Which of the 2 Petronas should I choose?