What I did was shop tires and wheels after selecting my car. Maybe your country has an equivalent website? Knowing my tire size I looked it up and the next sizes up. My goal was to increase the outside diameter to make it taller so the gearing is increased. This way I go faster at lower rpms and get more mpg. Plan B was to get it to the point I could drive in sport mode and maintain mpg, but that didnt happen as I didnt go tall enough.
Tire sizes are this, tire width/tire height and rim diameter. I searched tire sizes for the following for taller tires:
175/85r15
175/80r15
175/75r15
175/70r15
No luck.
I then went wider and started over:
180/85r15
180/80r15
180/75r15
180/70r15
No luck and I repeated. I had to go to 205 to get a taller tire that route. I did however find if I went with 185/65r15 I could get a range of tires and they were about half an inch taller. Someone where recommended going smaller like a 155/85r15, but that was 20 mm narrower x4 and I didnt want to go that skinny.
So, using customer reviews I selected my tires and they were a few lbs lighter than what I had in oem size. I then went for the lightest rims I could afford, lucky 10 lbs each, but not the color I wanted.
Its a bit wide, so rolling fenders to make fit 100% as the new rims are 7 inches wide, stock 5.5 inches.
Luckly with my suv they had 3 sizes larger, so it was easy. That I went from 205/75r15 to 235/75r15 Went up a few inches in diameter, speed o is 5 mph off. Still can maintain mpg and can drive with traffic at 500 lower rpms. 500 rpms = 5 mph. So I cruse at 3000 vs 3500 for 60 mph.