"Cyn i'r petrol orffen."
Translation:Before the petrol runs out.
Again, its sounds as if the pronunciation of the r here (in petrol) is neither trilled or tapped but closer to the 'English r (as in 'train) and is easier to pronounce thus. I have noticed it seems to occur on 'trowsus' and 'adre' amonst other examples that fail me now. It is easier and I know that sense will not be lost but is it something we should do? Apologies for raising this again but I needed an example and am a stickler fir trying to perfect my pronunciation.
I see what you're saying. This computer voice isn't the best here. It's not exactly like English "tr", where the the tongue tends to curl back on the "t" in anticipation of the "r". In Welsh, since the tongue tip taps the ridge when it articulates both the t and the r, for tr it taps it for both t and r at the same time but rather than release in the shape it makes for normal t (flattish), it releases in an r-shape (hollowed or curved up slightly as it releases). So in essence, the t and r combine somewhat.
(What I've described there is how it happens in a southern accent. In the north, the tongue is further towards the teeth for t so the r combines less with it in tr and so sounds more rolled.)
Remember this is a computer voice, which is at best an approximation. The only way you're going to get good pronunciation is to listen to native speakers. Could watch these too.