Hello Gaz,
I think ‘…getting away with…’ are the operative words, but you are of course right in believing you can fit whatever brand satisfies the speed and load requirements - and your pocket!
As you will appreciate, the trade offs will include road holding ( in both wet and dry conditions), mileage you will get from them, noise levels etc.
You will probably find, as I do, that on simple longevity, you will only get what you pay for, and lesser brands tend to wear out quicker, and the miles/£ might well show when you next have to renew them - plus you’ve probably compromised on road holding into the so called bargain.
My advice for what it’s worth is to search for the best fitted prices you can find for premium brands, such as Michelin, then compare those prices with the best mid range you can find.
I’ve just done the same with a set for our humble A3, and eventually found a very good fitted deal on Michelins at ATS ( never found a good deal with them before, but…).
I had considered Uniroyal Rainsport, Vredstein, or Nexen, all of which seem to have had generally good reviews, and there were good deals from the likes of Demon Tweeks, Camskill etc., but by the time you add postage and local fitting charges, none of them worked out to be significantly cheaper than my deal at ATS.
Not sure if any of this will help you Gaz.
Kind regards,
Gareth.