sodaman

Well i was just cruising around tire rack to see what was available for the 06 18 inch wheels. as optional sizing it says 255/45 18 frt, rear 285/40 18 in rear. Can the stock wheel take that. I was under the impression it wouldnt go bigger than 255. Any input on the new 18 and what tire will fit?

calvin84

285's are too big...everything i have read says 255 is biggest you can go on them.

sodaman

I understand 255/45 , but if you go different on the profile, the width number can get bigger i think. I notice the tire rack mentioning 255 for front with 45 profile, but the 285, they are using a 40 profile. Not sure if this equals out to be almost the same size tire. Anyone with a lot of knowledge on the tires for 18's please chime in.

adrenalin

Not quite how it works. The sidewall is a percentage of the width. For example. 285/40R18 means the tire is 285mm wide and the sidewall is 40% the width of the tire. BFG 255/45 tire is 27" in diameter, the same as the 285/40, however the 285/40 requires a rim width of 9.5"-11".

You will not get a 285 to fit the stock rim.

sodaman

well heres a tidbit I just found adrenalin, how about this size. This is a posted wheel package at sean hyland motors.

18x8.5 5 Spoke Konig Wheels, Anthracite spokes, polished rim lip, with 275/40/18 Toyo T1S tires, mounted and balanced.

It appears they are selling a 275/40 on a 18x8.5rim , which i believe is stock size for the 18's right.

Just trying to figure out the nicest size I can get on them. If this is correct, then we know a 275/40 would fit. Any more suggestions please fire away.

adrenalin

You lost me there. Not sure what you point is. Of course a 275/40 will fit on a 8.5" wide rim. That is not as wide as a 285. I am pretty sure the stock wheels on the factory 18" rims are 255/45's. If someone can confirm the size of the rim that would be great, but I though the factory rim is 18x8 with 255's on it.

Dan, just remember, manufacturers will state recommended tire sizes for different rim width's. That doesn't mean you can't go outside that range, but that does mean you now have a potential safety issue and if you have a problem with the tire, if it is not installed on a recommended rim size, you might void the warranty.

sodaman

Im with you adrenalin. I was told the stock 17 is 17x8, and the stock 18 is 18x8.5. Now if someone can confirm that, then it sounds like I could go as wide as 275/40 18 is that correct adrenalin. if it is an 8.5" rim. thanks for your help

this is from stangkc page listing about the bullits:
Ford is Finally Releasing the 18x8.5 OE Polished Bullits

adrenalin

Depends on which manufacturer you go with. I will use my tires for an example. BFG Gforce TA-KDW-NT. Biggest they recommend on 18" rims up to 8.5" wide is the 255/45.
The following are the recoomended tire width / rim widths

265/40 (and 45) 9.0-10.5" rim
275/40 (and 45) 9.0"-11.0" rim
285/40 9.5"-11" rim

however, the 285/60 can fit on an 8"-10" rim, but that is a big sidewall. tire is 31.5" in diameter, so that would not fit on the mustang.

To maintain the same overall diameter of the stock tires, you need to stick with a tire that is 27" in diameter. The BFG 255/45 is 27" in diameter.

However, as I said, it all depends on the manufacturers recommendations. I don't know what they are for Toyo, but BFG would tell you not to mount their 275/40 tires onto an 8.5" rim because it is not recommended. Doesn't mean shops wouldn't install them though. I once put tires on my truck that required a 10" wide rim and I put them on an 8.5" rim. Worked great for a few months but then took a corner too fast and blew both front tires out.

flight96

Since we are talking tire/wheel sizes, what is the widest tire you can put on the 17" bullitts? They come with 235/55ZR17. Also can I put a wider tire in the back and leave the 235's on the front?

adrenalin

Widest on the stock 17" is 255/45. And yes, you can leave the front's as 235's and put 255's on the back.

I have 255's on the front and 285's on the back, but that is because my rear rim is 18x10.

flight96

So I should probably go with 245/55R17 on the back? Also does the speed rating matter too much. Im putting these on my V6. The original tires, the 235's are "Z" can I put "H's" on the back? This way I waould have 235's up front and 255's on the back.

adrenalin

you should stick with the proper speed rating if you can. If you plan on driving over 200 kmh then ya, stick with Z

sodaman

Just too let you know adrenalin. The stock 18's, at least the polished ones. are definitely 8.5" wide. So with that said. I could do a 275/40/18 if i find the right manufacturer. Thanks for your help