You can consider buying amazon pay gift card from amazon using sbi cashback for 5% cashback and use it for fastag recharge. You can also share what other cards you have, based on which ppl can recommend.
Right, that's the only way even I see. I hold SBI Cashback CC, so, that's something even I had in mind.
I hold around 20 CCs but all of them are entry level cards or premium at max. but one of the promising card amongst them is HSBC Bank Live+ CC ... I even checked Blinkit voucher trick but that's over now as MCC for voucher purchase doesn't come under grocery anymore.
For Smartbuy, I hold HDFC Bank Regalia CC which isn't great as compared to SBI Cashback CC. Only if I had Diners Club Black CC or Infinia CC, then it would've made sense.
I'll stick to SBI Cashback CC for now then but I would love to know any other trick which could give more than 5% reward rate. I use IDFC First Bank FASTag for refueling (at HP pumps), so, I recharge Rs. 10k monthly without fail (min. KYC) and I'll upgrade to full KYC so that I can increase my monthly recharge limit.
Considering the E20 fiasco, it's even more necessary for me to save wherever possible as the mileage has dropped but the fuel price remains the same and I refuel 95 octane petrol which now also has 20% ethanol.