My Brother got the use of a 4th hand 1600 Mk2 Cavalier years ago when he was working for a company, had been totally neglegted.
He got the go ahead to spend money and service it, new disk,pads, filters etc.
The car struggled to get up the hill past Greasbrough dumpit site (the Rotherham Lads will know what I mean) and more often than not he had to change into 2nd to get to the top (not really a steep hill at that) Anyway, he dropped some wynns oil flush in, had a run round, left it to drain for a couple of hours and filled it with some fully Synthetic Castrol or similar brand oil. He also put some slibk 50 in at the same time. No idea why he used both.
Results were far better starting in the morning, lot better Mpg, but the main thing was the car went up past the dumpit site easily in 3rd gear and occasionaly in 4th.
He reckoned the slick 50 was the biz. I said the full service and good quality oil probably made the main difference, plus new air filter. He said the brakes hadnt been binding or anyrhing, and the old air filter looked as new.
So to this day I could never say if the slick 50 made a difference to the engine or not, one way or annother there was big improvement with the car. Not bad for a car that had done over 300K even if it was the 4th engine.
