Hi Guys,
Went to fill up the CC (Diesel) at my local Costco (Chadderton). Noticed on the Super Unleaded pump that its now 99 RON - Im sure it used to be 97 RON. A quick search indicated the fuel supplier to Costco is Greenergy whol also supply Tesco. Im assuming that Costco Super unleaded 99 RON fuel is that same as Tesco's Momentum 99 RON Fuel.
Forget to see what the price was for Costco Super Unleaded but im pretty sure it is cheaper than Tesco.
Hope this helps some people!
Rich
EDIT: link to Costco's magazine giving more info on the fuel
https://srv-file1.gofile.io/download/w1ry3d/785ba8c580bf94bda735aa3b2fbcd1e2/Costco-Fuels.pdf (Originally linked on scoobynet)