I was just watching a video about Gustav Eiffel, the designer of the Eiffel Tower. And I noticed the narrator was pronouncing his name ee-fell rather than eye-full, which is the pronunciation I’ve always heard.
Is ee-fell the correct pronunciation in some contexts? Is that the way French speakers pronounce it? Or does the man’s name have a different pronunciation than the tower? Or was this just an error by the narrator (who is suspect might have been an AI)?
I think that the French pronounciation is more like ee-fell, but I’m no linguist.
On a related topic, in UK math classes Euler was always pronounced ‘you-ler’, but recently I hear him called something like ‘oiler’, which may be more authentic for the time?
I remember in HS French class the audio that we listened to pronounced it as in the OP, “eff-el.” Wiki agrees. But once a word crosses languages, all bets are off as to how it ends up–as we all well know. I’m guessing that diphthong probably isn’t native/common en Français.
FWIW, I’ve never heard anything other than the oiler pronunciation
To my poorly-trained ear for French pronunciation, I hear what you note, with the observation that the ‘eff’ part is pinched a bit, leaving it very with a very slight flavor of ‘iff’ in the mix.
Wikipedia has an audio pronunciation:
And if you think that’s difficult, just try to pronounce parmesan 
Just throwing in that Eiffel got his name from ancestors who came from the Eifel region in Germany, which is, in German, actually pronounced eye-fel (with the stress on the first syllable). The French pronunciation is different though.
Native French speaker here. The trick is simple. Just say those two letters back to back: la tour F L.