Well if you think about it it's logical for the t5's and some vauxhalls and saabs to run bigger injectors. All of them have less cylinders and if I'm not wrong are turbo cars. As you know turbo cars run on richer mixtures (I've measured some factory turbo cars and some run low 11 as AFR at WOT in boost) hens they need more fuel and bigger injectors than a NA car i.e. a 200hp NA car needs smaller injectors than a 200hp turbo car reason is AFR .

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)