In case anyone hadn’t seen this, and I’m not sure how new this news might be, but I was in Tesco in Clarehall this morning and noticed their advertising for their 5c off offer on petrol and diesel.
The deal is that if you spend more than €50 in Tesco (with some exceptions) you’ll get 5c per litre off your petrol or diesel purchases with Tesco also.
Applies to Tesco in Clarehall, Clearwater and Dundrum.
This
website will save you money every time. 
I am coming over to Ireland for two weeks, staying near Waterville and Maam. I’m wondering what the cost of diesel is at the moment per litre as I need to budget for it. Would be very grateful for the current prices if anyone can tell me, or if there is a website in Eire for up-to-date info. Many thanks looking forward to seeing more of Ireland, William, (you can email me at penkeyman@btinternet.com)
Hi Anonymous,
The best you can get online for prices is the AA price survey which is updated monthly.
It’s available here – http://www.aaireland.ie/petrolprices/.
Enjoy your trip!