I have the Continental's and ran over something in the night that sliced a 6 cm gash in the front right. I will replace, and plan only both fronts. I don't want to replace with the Continentals (not great tyres) and want a different brand with same specs (225-40 R19 93Y). Any concern using a different brand / tread and if there is a valid reason to keep all four tyres same brand and tread?
Long story short. my winter tires are from the same brand but a different model. because they didn't had 35 and 40 with the same model.
so my fronts differ from the rear , never had any issues or noticed it
Here in the states, one of the least expensive tires (tyres) is the Firestone Firehawk Indy 500. Outside of the US, it is known as the Bridgestone Potenza RE003. It gets good reviews on TireRack.com and personally, I like it (especially given that it is half the price of the Michelins). Obviously, not the best tire but a great one and a VERY strong candidate for best bang for the buck.
Most suggest using the same brand/tread for reasons like friction coefficients between tires and wear rates, but I have run different brands/treads within the same type of tire (two different summer tires) until the other needed replacement without an issue. I would not advise running two very different tires together, winter and UHP summer for instance.
ask a good reliable tire retailer or google it ................I have an opinion but its just that , safety and performance are too important to rely on opinions .....................