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[PGabriel]

I've been thinking a lot of how to improve ride quality of the M3, due to the poor road conditions where I live.

Changing wheels/tires is out of the question, there are not many options available around, what I can find would not properly fit and is unbelievebly expensive.

So maybe decreasing tire pressure would help a little?

The door jamb sticker recommends 39.7 psi an all tires.

I tried to lower it to 35 psi but it didn´t help much.

That´s my question, how much lower could I safely go?

BTW I'm running 19" 220M wheels, NON-ZCP, stock suspension, tires Michelin PS2 245/35/19 & 265/35/19.

[THE TECH]

You have EDC? If so make sure you have it off. If not, I wouldn't keep lowering the pressure cause all you'll end up doing is getting the pressure sensors yelling at you. Unfortunately if the roads are that bad, then either larger sidewalls are your only option.

[Denk]

I know you're looking for a fix on the cheap but you're just not going to get there playing with tire pressure on your 19's. To really make a difference on crap roads, your best bet is running 18's. Proper tire sizes will have a taller sidewall and that'll make a difference. If that doesn't cut it...man, you've got some really nasty roads down there. Best of luck, I really hope you get it dialed in.

[akina335]

Originally Posted by Denk

I know you're looking for a fix on the cheap but you're just not going to get there playing with tire pressure on your 19's. To really make a difference on crap roads, your best bet is running 18's. Proper tire sizes will have a taller sidewall and that'll make a difference. If that doesn't cut it...man, you've got some really nasty roads down there. Best of luck, I really hope you get it dialed in.

I'll have to agree, 18's make a world of difference (for me at least). Anytime I swap out my 19's to my 18's I always say to myself how nice the 18's feel on the road. But as a general rule, 1-PSI or air pressure is about 40lb of spring rate. One time the tire guy put 40PSI in my front tires unbeknownst to me and the car felt very rough. OEM calls for 33PSI front on the 18's...he effectively increased my spring rate by 280lbs! I already have a stiff suspension setup with my KW's, didn't need it anymore stiffer.

[aus]

Get some used 18's. Otherwise, you got the wrong car.

[smmmurf]

You have to go to 18's or put soft all season tires on your 19s. Sorry, air pressure won't get you there without running unsafely low on 19's (25psi would be dangerous).

[PGabriel]

Originally Posted by smmmurf

You have to go to 18's or put soft all season tires on your 19s. Sorry, air pressure won't get you there without running unsafely low on 19's (25psi would be dangerous).

What about 30 psi?

[Z K]

Originally Posted by PGabriel

What about 30 psi?

That is a bit low... The lower your go with the PSI, the more risk you have of denting and damaging the rim. I'd rather have a rough ride than a dented wheel.

[schnell325]

You could go to 30 psi, but you will compromise the handling of the car and the life of the tire (ie: you will be wearing out the sides of the tires quicker than the middle tread)


You need 18's!

[vividracing]

Anything lower than 30 psi is venturing into pretty unsafe territory, and you'll see no benefits. In fact, you'll probably see a decline in comfort. You'll also greatly increase risk of damaging the wheels. 18s are your best bet.

[kmarei]

18s are the best options
i've owned both 18 and 19
no comparison when it comes to ride comfort
19s look great, but that's about it
on my current M3, i ordered ZCP but had the wheels removed before i picked up the car and replaced with winter 18s
also using 18s for my summer setup

plan B is to replace your 19" tires with a bigger sidewall
instead of 245/35 and 265/35
i was using 255/35 and 275/35
wider tire so better grip
and bigger sidewall so better comfort
a lot of people are using the 255/275 with great results

[PGabriel]

As I said before, I can´t change wheels to 18" right now.

I´ve heard Hankook's V12 tires are pretty comfortable.

The closest sizes to original I can find here are:

245/35/ZR19 FRONT
275/30/ZR19 REAR

Is it a good idea to improve ride comfort?

And those sizes will fit?

[JusCruzin]

If you can't switch to 18" wheels, then try an all-season tire rather than the Hankook V12. Bridgestone has a Potenza AS tire that I have on my other car which are very comfortable.

Out of curiosity, where in Brazil are you? I'm in LA where the streets are terrible (the worst in the United States). I've been to Rio, Sao Paulo and Brasilia and did not think the roads there were any worse than LA.

[PGabriel]

Originally Posted by JusCruzin

If you can't switch to 18" wheels, then try an all-season tire rather than the Hankook V12. Bridgestone has a Potenza AS tire that I have on my other car which are very comfortable.

Out of curiosity, where in Brazil are you? I'm in LA where the streets are terrible (the worst in the United States). I've been to Rio, Sao Paulo and Brasilia and did not think the roads there were any worse than LA.

We have a very limited brand/model tire offer here. No way I could get those Potenza AS.

I live in Santa Catarina (almost all the way down to the south). The roads aren´t terrible, but most of them are stone-paved roads, which makes the ride with the M3 quite unpleasant.

I found that lowering the tire pressure to 30-33 PSI helps, but I´m not sure it´s safe, since the recommended pressure is 39.7 PSI.

Still waiting for opinions about the Hankooks mentioned earlier.

[JusCruzin]

Stone paved roads on 19" wheels in an M3. Ouch. I doubt any tire is going to make for an acceptable ride under those circumstances. I also doubt that whoever gives you feedback on the Hankook V12s has ever tried driving them on stone paved roads, so I don't know that their advice would be meaningful for your situation. I would avoid any high performance summer tire and just look for a lower perf all- season tire available in your market.