[juicehound]

hey all just hit a manhole cover and blew out tires and 7k+ suspension damage later - time to lose the awful run flats and go with Michelin AS 4 tires but I need some help with tire options.

Car is an unmodified 2017 440i x-Drive Gran Coupe F36 w/ the BMW 405m 20" wheels:

https://www.shopbmwusa.com/PRODUCT/4...--COMPLETE-SET

I want the MOST sidewall I can manage without rubbing - problem is I don't know what the maximum diameter (height) tire setup I can run on the 405m's

using this tool here I came up with the following options: https://tiresize.com/calculator/

Options (Diameter smallest to largest):
square 235/35/20
square 245/35/20
staggered 245/35/20 + 255/35/20
square 235/40/20
square 245/40/20

please help me on this thank you so much!

[juicehound]

anyone?

[cfm56d7b]

While 20" 405M wheels look great, there isn't enough sidewall (run flat or go flat) to overcome the pot holes in the North East.

The best option: 18" wheels with the right tires.

Compromise: 19" wheels. I drove in the North East on 19" wheels and OEM staggered tires without major issues. Several pot hole encounters where alarming but no suspension or wheel damage.

[juicehound]

Originally Posted by cfm56d7b

While 20" 405M wheels look great, there isn't enough sidewall (run flat or go flat) to overcome the pot holes in the North East.

The best option: 18" wheels with the right tires.

Compromise: 19" wheels. I drove in the North East on 19" wheels and OEM staggered tires without major issues. Several pot hole encounters where alarming but no suspension or wheel damage.

I agree with you but staying with the 20's my question still remains unanswered.

[ade555]

I'm not a expert but looking at the link for the wheels fronts are 8j and rear are 8.5j so how you planning to achieve square setup?

I run 405 reps in 8.5j front and 10j on rear with tyres 235/35/20 and 275/30/20 on 4 series GC, from personal experience the front sidewall high is not enough, looks good but you can feel every stone and for that reason I'm going down to 19" but I will miss the look.

Front on 20s I don't think you can go higher then 235/35/20 as there is hardly any room left but I do have 8.5j with slightly different offset to yours, on rear you can get away with larger wheels and tyres.

[juicehound]

Originally Posted by ade555

I'm not a expert but looking at the link for the wheels fronts are 8j and rear are 8.5j so how you planning to achieve square setup?

I run 405 reps in 8.5j front and 10j on rear with tyres 235/35/20 and 275/30/20 on 4 series GC, from personal experience the front sidewall high is not enough, looks good but you can feel every stone and for that reason I'm going down to 19" but I will miss the look.

Front on 20s I don't think you can go higher then 235/35/20 as there is hardly any room left but I do have 8.5j with slightly different offset to yours, on rear you can get away with larger wheels and tyres.

thanks for this - do you have x drive?
it's so tough b/c there's SO many variables when it comes to these things - if you change one you have a question in your mind as to what is possible and what's not going to work

[ade555]

Originally Posted by juicehound

thanks for this - do you have x drive?
it's so tough b/c there's SO many variables when it comes to these things - if you change one you have a question in your mind as to what is possible and what's not going to work

No my RWD with m sport suspension. I didn't lower the car and been honest on front there isn't much space to do so. I can pm you some pictures later today.