There wasn't a lot of choice in petrol stations back then either. You could go to Campsa, Repsol or Cepsa stations. Campsa was the name of the old state company and the name belonged to Repsol by the time we got here so the fuel was Repsol too. Those two companies also controlled most of the refinery capacity in Spain. There is and was a BP refinery at Castellon and I'm told there were BP petrol stations too though I'd be hard pressed to remember having ever seen one.
Out here in the fields, to quote the Who, we still generally get attended service though there are now fewer attended service stations than there used to be. Lots of stations have attended service hours and card machines for the rest of the time. My guess is that in the bigger, busier towns and cities it's nearly all self service though most of the stations still have someone to look after the shop or to sell coffee even if they don't have much to do with selling fuel. I've seen lots of complaints from people asking why they should have to pump their own fuel, especially in the stations with no staff at all. Moans along the lines of - is it safe? - what about people with reduced mobility? etc. Some of the regional governments have even legislated against staffless filling stations on the grounds that they are safeguarding jobs. Ned Ludd is alive and well.
Nowadays there are more retailers though the choice is still quite limited; Galp, Petronor (which is actually Repsol) and Meroil are pretty common and there are occasional Shell and Agip stations. The big expansion though has been in the cut price suppliers. Cheaper fuel has been available in Spain for years now. At first the stations were few and far between and usually linked to supermarket chains but, now, they are everywhere. There's even one in Pinoso. Price differences are substantial. In the order of 12 to 15 cents per litre.
Spaniards tend to have shared views on things. Go swimming too soon after eating and you are going to sink. Drink hot drinks whilst you eat and expect health complications. Online shopping is risky. One of those certainties is that cheap fuel is poor fuel. The big brands, the known brands are safe but some unnamed fuel isn't. Some friends were assured by a main dealer that the reason the engine on their car packed up was because they habitually bought cut price diesel. When I've pointed out to Spaniards that all the petrol comes basically from the same refiners (Repsol, Cepsa and BP) their answer has been, as one, that the full price people put stuff into their petrol, that makes it good, whilst the cut price people don't, which is why it is bad. I've heard it so often that I half believe it and so I tend to fill up alternately with cheap and full price fuel. I never really believed it wholeheartedly though because I know that Spain is in Europe. I know that the EU puts controls on lots of things, amongst which, I'm sure, is fuel quality. If it says 95 octane then it's 95 octane, if it says Gasoleo A then it's proper diesel whether the stickers on the pumps say Bongofuel or Repsol.
Anyway, a couple of weeks ago as I accelerated the car onto the A31 the engine warning light came on and the power fizzled away. It wasn't a pleasant experience trying to get to the hard shoulder but the car fired up again and we got home. The chap who looks after the motor found a fault, a seal had gone on the hose into the turbocharger. He fixed it. Obviously he'd found the fault. But later the warning lamp lit up again. The second time I was in the middle of an overtaking manoeuvre. There was a lot of headlight flashing from drivers wondering why I had overtaken only to slow right down again. The mechanic had another go. He found clogged fuel filters. We had a conversation about fuel quality. He refused to be drawn on the question of cheap versus expensive fuel. He told me a story, a story that he stressed was only hearsay, about mislabelled fuel, cheap fuel sold as expensive fuel. I thought back to the day that the car first coughed. I'd been to a cheap fuel station.
Maybe I should be more careful about eating and swimming too!