Back in 2004-05, My mechanic used to pour Synthetic oil (Can't recall brand now) with Nulon on my Hero Honda Passion+. I also used to get Shell Super Petrol. Bike was running very smooth with this configuration and never had to kick it second time even during winters, mileage was 65+ always. I drove it for 55,000 KM, and sold it to a close friend who is still using it without any fuss.
I am not brave enough to try it on my TDCI Figo as there is no recommendation from Ford.
Just sharing my experience to help your decision.