HI,

This is a subject that was discussed on the forum but I haven't found a thread that really confirm this tire size compatibility with OEM mag wheel and issues that might occure.

My suspension is OEM, no lower spring installed.

New tires would be Continental ContiSportContact 5P

So, here are my questions:



Front:

• OEM wheel size is 225/40RZ18
• Mag wheel spec are 18x7.5''
• New tire I want would be 255/35RZ18 on OEM mag wheel. The outher diameter is the same but wheel width is 30mm wider (15mm each side)
• QUESTION: Is it a bolt on fit ? Any issues with tire rubbing ? Do I need spacer, if yes what thickness and have you found fibration issues with spacers?

Rear:

• OEM wheel size is 255/35RZ19
• Mag wheel spec are 19x9''
• New tire I want would be 295/30RZ19 on OEM mag wheel. The outher diameter is the same but wheel width is 40mm wider (20mm each side)
• QUESTION: Is it a bolt on fit ? Any issues with tire rubbing ? Do I need spacer, if yes what thickness and have you found fibration issues with spacers?

If anyone have such set up, can you show your pictures?

Tks 4 sharing your experience

Eric

 

I know there have been some 295s put on the rear without any problems, but going to a 255 on the front, might be too much.. I remember someone with a 245 having rubbing problems.....I have 235 front 275 rears on the roadster..
oh yeah, spacers. If you use hub centric spacers, you will be fine.

 

I have 285 35zr19's on my stock rear wheels. No rubbing whatsoever, lowered about an inch in the rear.

 

The 255's wont fit on the stock front rims, 7 1/2" is too narrow. If you did manage to get a 255 on the front rim it wouldn't fit on the car with the stock offset. I put 235's on the stock front rim and rubbed the suspension bolt. I had to use spacers.

Les

 

It appears that anything greater than 225 in the front will more than likely require spacers. I was looking at a 235 tire as well.

MoparFreak - since you said you lowered it one inch, what suspension are you running since you have no rubbing issues? I was looking at a 275/35 or 285/30 on stock rims however some have expressed concerns with a 285 on stock rims. I am looking to lower it one inch as well but I am concerned about rubbing.

 

I went with stock size in the new Generals. I wanted to go up one size to 235/40/18 and 265/35/19 in back. General does not make that tires in a 265, so I stayed stock to keep the sidewall height the same back to front.

 

Let me clarify about the 235. It didn't rub in normal driving. I had a credit card worth of clearance but under race conditions ...... I had to put spacers on.

Les

 

I rum 305/30/19 on the rear w stock rims and 245/35/18 front on stock n/a rims ......not had any issues and I have been to the track as well as lots of mountain curve carving here in CO. The tires I run are Pirelli p zero rosso's and they tend to run a little narrower in width. My avatar shows the back of my car with the 305's
Good luck

 

Tks for all your feedback. Finally I did the set up with 255/35R18 in front and 295/30R19 on the rear and YES this is working.

I put CONTINENTAL ContiSportContact 5P, amazing tire, grip like hell

Like it was mentionned by Velociabstract, I had to cut the extra lenght of the upper front bolt to create 5mm of space. No mechanical issue and no need of spacer.

The only esthetic issue is due to larger tire on narrower wheel, would need at least 1'' more of width to change the sidewall look. See pictures attached.

So, I am going to get a new set of black mat alloy wheel 18x9,5 and 19x10 with 10mm spacer and I will switch my Conti 5P on those for track racing (see mag picture). My wife doesn't like the black wheel at all!!!! But this is MY car

Now for the OE wheel, I am going to get a set of new Continental Extreme DW 225/40R18 front & 275/35R19 on rear.

I will post my new black wheel pics when on the car!


Tks to all!

 

I use to run slip and slide Hankook 285/35/19 on the back. Now I'm running almost an inch shorter 295/30/19 on factory wheels and suspension. No spacers-No rubbing. I can feel a faster pick-up with this shorter diameter tire. In two weeks I'll be putting 245/35/18 on the front. Don't forsee any problems there,for I'm presently running a taller slip and slide Hankook 235/40/18. Most tires with the same numbers on the sidewall can easily vary a half inch in diameter and width between different brand names. I'm now running Bridgestone Potenza S-04 Pole Position tires on the back and will be also on the front in two weeks Squirrel Crusher

 

Just a side note. Also depends on the tire brand since not all companies size the same. Like Pirelli which runs much smaller than the size suggests. I just ordered some of the new Nitto Motivo's for my coupe 235/40 front 275/30 rear so hopefully will not have issues up front and I am sure the rears will be fine since my couoe is just a limited I feel no need to go larger. I ran 285/40/18s on my 350z and still had traction issues but the square set up sure was nice in the corners as I had her pulling over 1.2 gs on the skid pad but still had lots of rear tire spin in 1st/2nd gear. My limited has less power and lower gears so I did the wider tires more for looks than need. Will post a review on the tires once I have had them a while since I have seen no thers running these 60k warranty was very appealing on these plus the run quite and handle better than the Conti extreme dws's.

 

So, I just got today my parts & new DaiAlloy Staggered Autobhan black wheel mounted with my new Continental ContiSportContact 5P tires.

Wheel: http://www.daialloys.com/wheel.php
Tires: Continental Tires -ContiSportContact™ 5 P



Front wheel project:

• I went 18x9,5 in front 35mm offset with a centric 16mm spacer.
• If you want to go 9.5 width in front you need at least a 15mm spacer, otherwise the wheel touch the connecting bar at the top. You also need to cut the extra length of the top bolt on this rod to avoid dammage on the tire. (see picture below with the red circle around the area)
• I tried with the 10mm spacer that I also had but there was no match possible in the front, only the rear with te DaiAlloy centric spacer. The center part of the hub on the Crossfire is to long (see picture below)
• Because of the spacer, I needed longer screw for the wheel, length is not an issue because you don't touch anything inside the disc. I went 12x1.50 17mm shank by 40mm long to match my mag and spacer width it worked.
• For front tire I went 255/35R18 Conti SportContact 5P. That is the biggest you can go. But for the next one I will go 255/30R18.

Rear wheel project:

• For the rear I went 19x9.5 25mm offset witn a centric 10mm spacer.
• 10 inches width would work also, but was not available with the wheel I choosed.
• The spacer was not mandatory but since I was larger in front, I wanted to balance the car.
• Rear tire are 295/30R19 Conti SportContact 5P. You can go bigger if you want, but for me it is way enough.
• IMPORTANT: For the wheel bolt, I had to cut 7mm of it in order to avoid dammaging the macanisim inside of the rear security brake drum. Make you test it by slowly spining the wheel to avoid problem.

Here are some pics of the project. You can see difference between OEM wheel with 225/40R18 front tire & OEM wheel with 275/30R19 rear tire. I also post difference betwen OEM & new black wheel in different angle.

I did a first road test and I have a light rubbing on the top of the front fender when I hit bumps. Since the front tire & wheel are going outside of the fender, it is no surprise. But I have room to make more clearance on the plastic splash guard with my Dremel.

If not enough, I will stiff the front suspension.

Here are the pics!

 

I just put Nitto 235/40/18 up front no issue and went with 275/3019 rear no issues up front at all.

 

So is it Nitto or General G-Max? If G-Max I would suggest to go 275/30R19, you would be less than 2% difference (smaller) than OE 255/35R19. Which is acceptable. But OE size are always the best.

 

I bought my car with a 245/45/18 on front with no spacers and no rubbing issues. Looks good too because it fills the wheel well a bit more. I do want wider and taller tires out back though and will when these wear out.

 

I thought about going to the 275 in the rear on the General G MAX, but decided with possible rubbing issues along with higher stress on the rear end and tranny I would just do stock sizes. When you get bigger tires it transfers stress somewhere else. The rear end and tranny on the 6 speed manual are not overly strong, I felt like it would have been ok as I don't beat it up. Bought the stock sizes ,so for me it is a done deal. The G MAX seem to have more traction than the stock tire anyway, so I'm happy.

 

Road test: I went for a ride and the actual front set up, 9.5 inches wide with a 16mm spacer makes the wheel rub the limit of the uper fender when hitting bumps on the road. So I will need to switch for a 10mm spacer max.

My recommendation for a bolt on larger set up would be to go 8.5 inches wide max without spacer if the offset clear the inner rod.

Again some time in the garage to make final adjustment... In the end, it is part of the fun doing those mod our self

 

So, how about that update?