Actually it all depends upon what fuel station you go to frequently, what card do you intend to use, how much you refill etc.
For me, I try to use Amex Platinum Travel and MRCC most of the time including fuel because it has awesome spends based benefits (all my other cards have fuel surcharge waiver but aren't as rewarding as Amex). Although Amex does not put fuel surcharge at HPCL pumps, I've observed significantly higher fuel economy when I refill from a particular BPCL pump which is 200 meters from my house. So per my calculation even when I'm paying slightly higher costs due to surcharge, I save much more due to better economy. If I had an option to buy BPCL vouchers without any additional charges, I could save even more by saving on surcharge + would get points.
@thespy12 Can you explain how this ufill voucher works and at all BPCL petrol pumps.
Can I buy bigger voucher and use less or full amount for petrol filling ?
Believe there will be no reward points on the rupay card as it will be considered as fuel payment