2007 3.0si tire & wheel size help

[mtc46jw]

Hi there;

Just got my Z4, its a 2007 3.0si auto with 12,000 miles. Ya I know its sacrilege to drive an auto for some of you, but as you get older you make concessions.

Heres my question for the collective. Can I buy 17" rims and mount 17" tires on my "Z"? I am looking for a more civilized ride (softer ride) than the RFT's are giving me.

In fact, I have never driven a car that is more brutal on secondary roads than this car. It also demands 2 hands on the wheel at all times snd is twitchy as hell at the best of times. Is this a function of the RFT's or the nature of the car?

With 20,000 kms on the original tires I suppose I'm getting close to the limit of wear on the RFT's. Do they get or behave diferently as they get older ort cloe to the limit of use?

I have looked at even just replacing the RFT's with non-rft's such as either Flaken 452's or General UHP's.

Does anyone out there have any experience with a 3.0si sport package and mounting 17" ers?

Will I notice a significant difference if I mount Non-RFT's? I mean really notice a difference? Will the harshness and tramlining be reduced "(gone).

Any advice you can give would be appreciated.

[Feyd]

i went from 17's with run-flats to 18's with the general UHP's and the ride is SIGNIFICANTLY better than it ever was with 17's. As far as sizes go, there have been people who have crammed 20" wheels on their Z's. So, 17's will be no problem.

[speedygirl]

I have a 2006 si roadster with the sport package (same specs as 2007 si roadster). Came with the 18 inch sport wheels. After some research I bought OEM 17 inch wheels for winter use as smaller radius is apparently better in snow. I have stock 18 inch runflats, and bought 17 inch Dunlop (runflat) wintersports and am very satisfied. Can give the rest of the specs if you're interested, but they are the same as come with OEM. Tire Rack is a good resource for research/purchase as well.

[fflores]

i believe that the problem is actaully the RFT's and not the size of the rims... I might have a set of 18's for sale soon

[mtc46jw]

Well....Thanks for all your replies. To be brief, I ditched the bridgstone RFT's and put on the General exclaim UHP's for a quarter of the price of the bridestone RFT's and could not be more pleased!

Tramming is significantly reduced, the bone jarring ride is greatly reduced, and the horrible noise from RFT's is gone! Just smooth sailing all way round!

Had it up to quick 100 mph and all is wonderful! Straight as an arrow!

If you're thinking about changing from RFT's to non-RFT's even remotely, thinking about it don't even hesitate! Just do it! its like getting a whole new car!

The only difficulty I had was getting someone competent to do it! Two tire shops refused before I found one that said, "no problem" we do lamborgini's, corvettes we can certainly do yours! And you know what....and They did.. and extremely well too, not a scratch, not even a mark on the 108 rims! reset the TPMS button and all done!

Why BMW put those shitty RFT tires on such a wonderful little roadster is just beyond me and its just criminal! IF they put on decent tires they would sell even more of them! Its just plain stupid!

I now have my little tire repair kit (for $29.95) that has a compressor and slime in a nice little container that fits in the corner of the trunk as insurance. So I'm good to go! and off I will go!

cheers & beers

[3002 tii]

ironic b/c the m cars don't come with rfts but they peddle off the rfts to be great performance tires!

[DerekSelmanRacing]

Don't condemn rft totally. I agree with all the comments concerning rft on the Z4.

We owned a 2006 350Z which came with the same Bridgestone rft as the Z4, only in different sizes. My reaction as soon as seen was that they would be replaced shortly. Surprise, ride, handling, and performance, even on track, was very good.

It's something about the lack of compatibility of the Z4 suspension setup withe the rft.

[3002 tii]

i dunno but i find the rft's arent great in wet weather, and when i hit the ramp coming onto the freeway, i always lose traction 2nd going into 3rd.