tire size

[h2oyo]

Hello,
On my 95 540i I am now driving on 225/40/17's all around. I dont want to go to staggard rims but would like to go to wider tires. Is 235's just about the widest I could go up front thus making this just about as wide as I can go without changing things. I was also thinking about going to 45 series tire instead of the 40's not because of the ride but because the streets I have to drive have alot of train tracks and pot holes. Everytime I hit one the car thumps really hard. I was hoping that the 45's would help with this. I also thought that the 45's will fill the wheel well more and maybe it would look better as my car is lowered. I would like to lower it more but its already hard to get a floor jack under the front. I can only get the jack under the car behind the front wheels and then its just barely lol. What ideas do you guys have. I have seen alot of really tough cars on this forum and trust your judgement.
Thanks in advance
Johan

[Tiger]

235/45R17 is the actual recommended tire size for E34. You are running too small of size by a large margin. You should change your sway bar links if it bangs when you hit a puthole.

[h2oyo]

235/45R17 is the actual recommended tire size for E34. You are running too small of size by a large margin. You should change your sway bar links if it bangs when you hit a puthole.

Thanks for the reply, I will up size my tires, The swaybar links where changed about 4 months ago. When I hit a pothole or uneven surfaces like train tracks or where blacktop and concrete meet I get what I believe is a like a wheel slam. It is very hard and I don't have to be moving fast just it the dip or hole or track. I thought maybe I had the bumper stops in my front shocks. The PO had them installed, I lowered the car with springs. I have checked and they are billy sports and I installed eibach springs. The rear will do it also but not like the front, I thought maybe the tire size? I thought the tires where on the smaller size, that is why I was thinking 235/45 17s instead of what I am running 225/40/17's. The tire would be a little bit taller and wider so it would help with taking in the track, pot holes concrete to blacktop changes etc. What do you think, am I just dreaming and there is a much bigger issue with the car? Again thanks and I appreciate the help.

[Tiger]

Yeah, I got the same setup... it is the tire... when I got the car it had Nitto NT555 tire on it... it is real rough when hitting pothole. I downsized the wheel and tire to 225/50R16 with Bridgestone tire... it is better but still rough when hitting pothole. Now I am using General UHP Exclaim... and I am very happy now... the car ride so smooth and comfortable with great traction.

[h2oyo]

Yeah, I got the same setup... it is the tire... when I got the car it had Nitto NT555 tire on it... it is real rough when hitting pothole. I downsized the wheel and tire to 225/50R16 with Bridgestone tire... it is better but still rough when hitting pothole. Now I am using General UHP Exclaim... and I am very happy now... the car ride so smooth and comfortable with great traction.

Yeah my car came with the stock 15 inch wheels and 225/50's. I changed the rims to 17's and I got 225/40's I think that was my mistake. I'm going to change the tires size to 235/45. I'm not looking for a sily smooth ride I like to feel the road, I just dont want the wheels to bang like they do over the potholes and uneven surfaces. The 235/45's will be wider and taller sidewall so it should help with the bumps. Thanks for the responce.
Johan