[Tiptop2000]

I wonder if anyone can help, my wife has had a G30 530D touring for 6-months in the UK. Its been fitted with the 20" 669M's on it. Here is the chain of events:

1. Got a sidewall bulge on the passenger front after hitting a pothole in Cheshire (UK roads are dire). Replaced all tyres from RFs to PS4s's as the ride was harsh as well.

2. Rear passenger side flat, turns out to be a cracked rim. New rim & new tyre.

3. Hit another pothole last week, new bulge on the driver front.

We love the car but am losing the will to live. Can anyone recommend if we go down to 19" or 18" wheels? What have others done in this situation.

Thinking we either sell the car and get an SUV or sort the wheel/tyres out.

HELP, as we are at a total loss as to what to do next. Concerned we change to 19" and have the same challenge. Or move to 18" and also have a similar challenge. Plus, will the wheels at 18" look any good on a 530D.

So many questions, any help or pointers would be amazing.

[Boosted_8]

If you like the car I would drop down to 19" and upsize the non run flats. I hate SUVs but can see why they are popular with the state of the roads. I'm in east Cheshire and took out a near side front 20" rim in a pot hole 3 weeks after getting the car!

[AiwenD]

You can go for the 19 inch, since the tire will have a thicker sidewall. But you can also try to slow your speed when appoaching a pothole.

[TEF]

No matter one's rate of speed, 20-inch wheels and tires are easily damaged, so it's unfair to blame someone for driving too fast. Here in the colder parts of the US, it's not unusual to hit winter potholes that are hidden under puddles of water on expressways. Since they're not visible, there is often no time to slow down.

Given the all the damage so far, I would suggest going with 18-inch wheels and tires. The combination offer cheaper wheels and tires. Moreover, the sidewalls on tires with a 45 profile offers even more protection than the profile of 19's. Even when not hitting potholes in Cheshire (reminds me of lyrics of Beatles' "Day In the Life"), one will enjoy a much better ride.

[WretchedRefuse]

What TEF said about hidden potholes. Plus I think that you can do 45-profile tires on 19" rims as another option. I know that others on this forum have done that so feel free to chime in on your experience.

[Alscoob]

I have 20's on my 540 G31 and so far generally okay, but do spend a lot of time looking at the road ahead and dodging poor surfaces where I can and I still have run flats on, I will wear them out, then shift to non rft. However, I do think that this is what you have to do with these types of designs where aesthetics outweigh practicalities and is something you have to think about when buying the car. If you are a person who just wants to get in and drive and not worry about the tyres and poor road surface combinations, then you will definately need smaller wheels with larger tyres but then that still doesn't negate pothole damage totally.

I used to run 19's on my 340i F31 so 255x35x19 in the rear 225x40x19 fronts, non runflats and in 72k miles no problems of cracked wheels or tyre bulges. So, on that experience I would suggest opting for 19's and going with 275x35x19 rear & 245x40x19 front. which actually gives you a taller tyre wall than my F31 sizes.

Also my missus has a Z4 and that originally came with RFT and 30 rear and 35 front profile, she had a cracked rear wheel just after buying it with 18K miles. Have kept standard sizes but added non run flat tyres, cars now on 93k miles all wheels original, no cracks.

The alterantive is to consider sticking with the 20's and using 275x35x20 R & 245x40x20 Fronts, these sizes are near as dam it identical in circumference, better than the standard sizes, so you have a greater % difference allowable as they wear. (standard sizes are already around 1% difference at new).

Haven't done that myself but some have on here. Gives the tyre a bigger look but that will help fill the huge wheel arches I guess.

Personally I wouldn't go smaller that 19's as I think that the actual wheels will then just look too small for the car and the feel and driveability will potentially suffer. 18's for a winter option is fine where you are concerned more with traction than handling.

Hope that helps a bit?

[MRDILLONS]

Went through that as well, recently had 3 cracked rims with some crappy Goodyear runflats. Changed them to regular PZero A/s plus 3 tires 245/40/20 & 275/35/20 and feel way more confident going over bumps now.