Did sort of have a thread on this on the old forum, but don’t think it was updated much lately. But it never hurts to know where you can find a “bargain”.
Bienne/Biel Brüggstrasse - 2 stations - one on either side of the road - both offering petrol at 1.689 and diesel and 1.759 a litre.
I found this mostly accurate:
A 5rp difference is 3sfr per tank. I fill up my car twice per month maybe. I don’t even know what gas costs at the moment.
Given that prices local to us are in the 1.90’s for diesel being able to get it for 15 or more cents less is great. Didn’t have to go out of our way either as we passed those 2 stations on the way to Altreu to see the storks. They’re regularly the lowest ones to be found on our route through Bienne.
We do have one station locally that’s down to 1.81 for diesel, but even so we saved 5 cents getting it in Bienne.
We don’t fill up often either now hubby’s retired. Once or twice a month depending on where we go during the month.
Cheapest for 95 leadfree in CH is 1.61 at Motel Noirval Gas Station Building 78, 2807 Lucelle. Cheapest in La Côte is at two ENI stations near Rolle 1.75.
Based on TCS website linked above.
That’s pretty good - around my area, cheapest is around 1.90 for unleaded.
Filling up 2-3 times a week around 80 liters, it makes a difference…
Yabut Rolle is too far from here to make it worthwhile to get fuel there. Around Nyon it’s 1.89-1.96. With my Coop 6 centime voucher I can bring it down to 1.83.
The coop in Grützi Markt in Winterthur has been renovating their garage since April. Parking is free in the garage and diesel was 1.74/liter this week. Renovation is almost over though, so I don’t know how much longer that will last.
Stations mentioned in the OP are now down to 1.679 for diesel. Didn’t see the petrol price, but it will be lower too.
Also if you need AdBlue the Migrol station at Hauptstrasse 87, 2563 Ipsach does it for CHF0.74 a litre, by far the cheapest we’ve ever seen.
Drain out your neighbours tank. Easy!
Well shoot. One of the cheap petrol/diesel stations in Bienne has closed down. 
Used to fill up there whenever we passed through. Was going to do the same today, but out of luck.
For those out my way, get thee to Churerstrasse, Pfäffikon SZ.
Both the Etzelpark Tankstelle and the BP are consistently lower than others in the area.
Only downside - everyone in the greater area knows this. You may have quite a wait in line!