F13 tires 21”

[Chase1]

I have 21x9.0 +25 front and 21x11.0 +45 rear
What size tires should I run
Please help lol
I was thinking 305/30 in the rear but not sure if that’s too much

[Rsnk60 M6]

I ran 325/25/21 rear tires on mine

[Wheel man]

I would do 295/25/21 rear and 265/30/21 front if you plan to lower the vehicle. If not I would run the 305/30/21 in the rear. I attached a 21" tire chart below to help your math.

[Chase1]

Do you think I could get away with a 295/30 in the rear? I’m having kw coilovers installed but I also want the meaty look

[Wheel man]

It's a 1/2" difference rear to front tire but it will work with the KW kit. I put 20*11 and 9.5 wheels on a friends M6 and ran a 315/30/20 in the rear. (As requested) I have attached a photo to give you and idea of the look. He was not happy with the look of the 30 series in the rear because it was so tall. But it doesn't rub or anything like that.

[machareus]

I have stock suspension and stock wheels (20x9.5 front, 20x10.5 back), but I opted for taller sidewall to better manage the terrible roads in my area. Went with 305/35-20 in the back and 265/40-20 in the front.

Those tires are 28.3" tall in the front and 28.4" tall in the back (pics below). The backs don't rub at all but the fronts experience a slight amount of rubbing against small protrusions in the wheel well liner. This only happens when the wheel is turned at a specific angle. I've seen no tire wear from the small amount of rub in about a month of driving them.

305/30-21 would be 28.2" tall, so with a 0.5" drop I think you may encounter an issue with fit.

ETA: 295/30-21 would be 28" tall, so that might be okay but it would be really close. The best match for front would be 255/35-21 which is also 28" tall, but I think with a 0.5" drop you would experience worse rubbing than my tires. Also my offsets are stock.

[Chase1]

So if I were to run a 295/30 in rear what should I run in front? 🤔

[brad850csi]

One thing that nobody has realised yet is that Chase1 profile says 650i, but we are all talking about M6 setups.

The M6 setup is 20mm wider tyres front and rear with a completely different rear axle and wider front flares so any offset discussion isn't relevant between what we know as M6 people vs this setup.

The stock 650i tyres are only 26.8" front and 26.5" rear in height - they are 245/35r20 and 275/30r20.

With that stock height and your wheel widths I think you might be in a tricky spot - my thought would be 255/30r21 and 295/25r21 but the rear will be fairly stretched. I think that 265/30r21 and 305/25r21 might be a bit tall and you may start to struggle with clearance on the front suspension and wheel arch liner on turns but you might want to wander around the normal 6 series forums a bit more to look at what those guys are running

[machareus]

Originally Posted by brad850csi

One thing that nobody has realised yet is that Chase1 profile says 650i, but we are all talking about M6 setups.

Good point - hadn't noticed that.

OP could try giving Tire Rack a call. They have laser measured several cars and may be able to give advice on what could fit. They had not measured an M6 though.