6-8k 100 mile commute 4x a week. Petrol or Diesel?

Hey All,

This has been covered in parts but would like a reply with updated options and opinions. I do 18k a year mostly motorways and looking for a vehicle that will last me a a good few years for commuting for around £6k-8k

Diesel makes sense for that many miles annually I have read but with upkeep and having to get euro 6 min (my work now in the border of ULEZ. Thoughts and vehicle suggestions?

Are Mazda diesels as bad as I’ve read? Are focuses comfortable enough. Octavia and golf tdi seem the most suggested. I had some links as options but I can’t post links yet as a newbie. Newer Mondeo? Do newer deisels still last 150k well maintained.

I saw a post suggesting just get a cheap reliable (cheaper to maintain) petrol Vectra and save the up front cost? But I do a fair old commute so I’m thinking just invest in soemthing I like.
That’s comfortable and economical.