/40 front, 45/ rear tires?

[khc3]

OK, I'm still figuring our the tire codes, but if I'm correct, using /40 profile tires in front and /45 tires in back will retain some semblance of the factory "rake." Will they look stupid on the factory wheels? Too low? Any reason why I shouldn't/can't put these on my car?

thanksin advance!

[SergntMac]

I've been scratching my head over this junk too, and I think the 40/45 issue can be affected by the tire width. In tire code, a "255/45/18" tire is 255mm wide, with a 45mm tall sidewall, for an 18" wheel. Our OEM 18X8 rims will take up ro a 265mm wide tire without rolling the sidewall out of shape. Let's look at tire sizes I'm considering as an example of how this can affect the OEM rake, and not disturb the ABS.

If I mount 255/40 tires in front and 295/45 tires in the rear (on wider rims of course), the car will retain the OEM "rake" and not set off any alarms. This is because the 40 is 40 percent of 255,(=6.3) and the 45 is 45 percent of 295(=6.5). As the tires get wider, the sidewall needs to increase to retain the rake.

If you don't care about the rake, neither does the car. You can run 40/45/50 whatever sidewalls on all four corners. You can go as wide as 265 on the stock rims, but 275 and up need more rim. The rear wheel well can take up to a 305 wide tire, but I would not go past 265 wide in the front. keep in mind too, that the shorter the side wall, the less shock absorbtion by the tire. Those 35,, sidewalls look cool, but ride like housebricks.

[Marauderman]

Mac-
Thanks for further in-put on this issue--as you might /would expect--am looking for extra wheels so I can get wider (9.5) like your looking to do and to get wider as your wanting to do--so any help on all this helps--- only if I can remember to write down all the stuff from so many threads--gotta be a better way--geesh!

[Marauderman]

HeY Mac-

Just noticed--we're Member 392-- 393 --Hummm--and both with S/C's so close----Hmmm what'ya think-- at least we're close in "numbers".. :lol:

[SergntMac]

Yes, and in age too, Tom. Have you come down from Cloud 9 yet?

khc3...I forgot I had this handy site, check here for your correct tire size. Note that it will give you the tire height, if you enter the width, sidewall height and wheel diameter. As long as the front/rear are within 1" of each other, you'll have no problems.

http://www.speedworldmotorplex.com/calc.htm

[Marauderman]

Originally posted by SergntMac
[B] Yes, and in age too, Tom. Have you come down from Cloud 9 yet?


Hey -Mac- Need to discuss that cloud 9 factor---will e-mail you tonight...Tom

[khc3]

Thanks Mac. At this point I am leaning toward doing the 255/40/18 in front and get my rear wheels widened and put 295/45/18 in back. I think the Nittos come in these sizes. I just hope thhe lower-profile tires don't look under-proportioned in the MM's wheel wells.

[SergntMac]

Originally posted by khc3
Thanks Mac. At this point I am leaning toward doing the 255/40/18 in front and get my rear wheels widened and put 295/45/18 in back. I think the Nittos come in these sizes. I just hope thhe lower-profile tires don't look under-proportioned in the MM's wheel wells.

Good pick on the tires, you'll like the new grip. Sorry I can't picture the overall appearance once they are on the car. You may want to check that front size one more time. 40% of 255 vs. 45% of 295 is a remarkable built-in rake. I think 45s all around would be an option to consider, and still retain some rake. Nonetheless, if you don't like the end result, you can opt to lower the front with Eibach springs, and adjust the rear height yourself. Happy motoring!

[khc3]

I understand now about the "profile" being a ratio, so the 255/45 and 295/45 on wide wheels does sound like what I'm looking for. Thanks for the guidance!

[VandaLL]

hello! long time lurker, first time poster. i recently acquired a 99 crown vic PI, and want to get some nice wheels. after considering the various mustang wheels, i really want these saleen re-pops:
http://www.wheelreplicas.com/sstyle.htm
in the 18x9 size all around. aren't the marauders and the CVs (which there seems to be no one running 18s) the same exact set-up? in other words, will these wheels fit on a CV lowered ~1.5"? i realize with that width, the clearance in the front will be strained and i was still hoping to put on a tire with at least a little overhang to protect the wheel lips. does anyone have recommendations for tire sizes for these particular wheels? and of course optimally the overall height would be around the same to not screw the speedometer up too badly.

thanks, with any luck i will soon be too cool for school just like the marauder crowd! :beatnik:

-Randy-

[SergntMac]

i recently acquired a 99 crown vic PI, and want to get some nice wheels. in the 18x9 size all around. aren't the marauders and the CVs (which there seems to be no one running 18s) the same exact set-up? in other words, will these wheels fit on a CV lowered ~1.5"? i realize with that width, the clearance in the front will be strained and i was still hoping to put on a tire with at least a little overhang to protect the wheel lips. does anyone have recommendations for tire sizes for these particular wheels? and of course optimally the overall height would be around the same to not screw the speedometer up too badly.

Randy, there are remarkable differences between the '99 CV and the '03 MM frames, and I going to suggest you recheck your specs. The MM uses a 50 MM offset wheel, which means that a lot of the wheel and tire is loaded on the inside. You may have some fitment problems on turns with the front suspension. I know for a fact you're going to have problems in the rear, if you depend on MM specs. The Marauder has a new "hyrdoformed" frame, as do all '03 Panthers. The rear shocks are mounted on the outside of the frame, and if you use the wheels you suggest AND lower the car, it's not going to work.

Maybe you could hook up with an MM owner near you, and negotiate a wheel exchange for testing?

Also, take a peek here:

http://www.karkraft.com/wheels_&_tires.htm

You can get OEM Mustang wheels, somtimes with a tire combination that WILL fit your '99 CV. Good luck!

[Marauder]

If I mount 255/40 tires in front and 295/45 tires in the rear (on wider rims of course), the car will retain the OEM "rake" and not set off any alarms. This is because the 40 is 40 percent of 255,(=6.3) and the 45 is 45 percent of 295(=6.5). As the tires get wider, the sidewall needs to increase to retain the rake.
I think your math is off. 40% of 255 is 102mm = 4.02 inches.
Your thinking of 255/45-18. 255 * 45% = 114.75mm = 4.51 inches
50% of 235 = 117.5mm = 4.63"
55% of 245 = 134.75mm = 5.31"
45% of 295 = 132.75mm = 5.23"
1/10" isn't too bad.

I think a 40 series front in 255 with will look too small...as in the diameter. I myself will be doing 255/45-18 up front and 295/45-18 in the back with widenend rims. The car will have the same rake and the profile of the tire will be close to stock. :D

[Marauder]

Randy, there are remarkable differences between the '99 CV and the '03 MM frames, and I going to suggest you recheck your specs. The MM uses a 50 MM offset wheel, which means that a lot of the wheel and tire is loaded on the inside. You may have some fitment problems on turns with the front suspension. I know for a fact you're going to have problems in the rear, if you depend on MM specs. The Marauder has a new "hyrdoformed" frame, as do all '03 Panthers. The rear shocks are mounted on the outside of the frame, and if you use the wheels you suggest AND lower the car, it's not going to work.

Maybe you could hook up with an MM owner near you, and negotiate a wheel exchange for testing?

Also, take a peek here:

http://www.karkraft.com/wheels_&_tires.htm

You can get OEM Mustang wheels, somtimes with a tire combination that WILL fit your '99 CV. Good luck!He's right. CVs use about a 15mm offset. I had an 18x8 with 30mm offset rims on the front of my 2002 CV. The inner rim lip was extremely close to the upper ball joint...as in less than 1/4"!!! Any more offset and it was going to rub. Imagine another 20mm!!!

PS: The Crown Vic on http://www.karkraft.com/wheels_&_tires.htm is my old 2002 CV. I bought my rims from there but sold them a year later. Those rims fit nicely. I had 245/45-18 up front and 275/40-18 out back. :D

I saw a guy that put 2003 Town Car rims on his 2000 town Car and it looked ridiculous...like the car was doing a balancing act because the wheel were so close to the center of the car...lol.

2003 Panthers have an entirely redisgned suspension...The new offset on the 2003+ panther rims rivals wrong-wheel-drive.....errr, I mean front-wheel-drive cars. :D

[VandaLL]

Randy, there are remarkable differences between the '99 CV and the '03 MM frames, and I going to suggest you recheck your specs. The MM uses a 50 MM offset wheel, which means that a lot of the wheel and tire is loaded on the inside. ... You can get OEM Mustang wheels, somtimes with a tire combination that WILL fit your '99 CV. Good luck!
Sergnt, thanks for enlightening me, i obviously had no idea they are such different chassis'. i wasn't going off of any specs, but rather just assuming, and i know what they say
:nono:
these wheels i am looking at are less than half that offset at 24mm, and are the same specs as OEM mustang wheels as far as i can tell. i was just worried about clearances with such a big combo..

-Randy

[VandaLL]

He's right. CVs use about a 15mm offset. I had an 18x8 with 30mm offset rims on the front of my 2002 CV. The inner rim lip was extremely close to the upper ball joint...as in less than 1/4"!!! Any more offset and it was going to rub. Imagine another 20mm!!!
so.... 18x9s with a 24mm offset would work?? *praying* i know that guys who put bullitts on their CVs usually have to use spacers up front to clear certain components.

re: ps: where is your car? i looked through all the sections and cannot see one CV.. if its not on there anymore can you post pics or email them to me?

yeah, 50mm offset seems huge! is the frame notched in a lot more at the axles than past models?

thanks again,
Randy

[studio460]

khc:

I went through a long process trying to figure out the same thing. Click here for the detailed thread I started a while ago with all the specs and calculations . . . (http://www.mercurymarauder.net/forums/showthread.php?t=5581&highlight=lower+series) I finally decided on the Nitto NT-555 245/40 ZR18; 255/45 ZR18 front/rear combination. This allows me to maintain the exact same rake as the factory set-up. I am only planning to install these with a concurrent install of the the Eibach springs, since I think the lower-series tires would look funny without some lowering added. One last call to Nitto I wanted to make was to make sure the sidewalls of these size tires could take the load our heavy cars would put on them. I'm dying to put these on and do the Eibachs but my factory tires are still good!

[SergntMac]

I think your math is off. 1/10" isn't too bad.
Yes, I see that, thanks for correcting the math.


I think a 40 series front in 255 with will look too small...as in the diameter. I myself will be doing 255/45-18 up front and 295/45-18 in the back with widenend rims. The car will have the same rake and the profile of the tire will be close to stock.
I agree. Not only will the 40 look out of place on such a large car, the ride will suck too. However, my point was that this mix would be tolerated.

Math aside, we end up with the same suggestion. Match the tire height on all four corners, the tire width will result in a natural and pleasing rake.

Keep in mind that you lose any opportunity for rotation that extends tire longevity. Most of the tires offered in these sizes are directional, or are mounted "this side out." The only rotation possible is a side to side switch, requiring mounting and balancing too. So, unless you really need the wider tire in back for traction, I sugest you match all four tires, and rotate front to back every 5-6K miles. You'll get more bang for the buck out of your tire investment. Happy motoring!

[Marauder]

so.... 18x9s with a 24mm offset would work?? *praying* i know that guys who put bullitts on their CVs usually have to use spacers up front to clear certain components.

re: ps: where is your car? i looked through all the sections and cannot see one CV.. if its not on there anymore can you post pics or email them to me?

yeah, 50mm offset seems huge! is the frame notched in a lot more at the axles than past models?

thanks again,
RandyDAMN!!! They took my car off their page. :down:

Here's the picture they "HAD" on their page:
http://www.imagestation.com/picture/sraid50/p127dc18c91cca2aa2d09fe8a1b6d2 8dd/fca801f2.jpg

Quite a few guys have fit 18x9 or 17x9 Cobra R's with 24mm offset with little or no issue on pre-03's. I think they ran a 1/4" spacer up front to minimize sway bar rubbing at full lock. Otherwise, there should be no rubbing. 1/4" still leaves the rims hub centric and there is enough thread on the studs.

[Marauder]

Yes, I see that, thanks for correcting the math.



I agree. Not only will the 40 look out of place on such a large car, the ride will suck too. However, my point was that this mix would be tolerated.

Math aside, we end up with the same suggestion. Match the tire height on all four corners, the tire width will result in a natural and pleasing rake.

Keep in mind that you lose any opportunity for rotation that extends tire longevity. Most of the tires offered in these sizes are directional, or are mounted "this side out." The only rotation possible is a side to side switch, requiring mounting and balancing too. So, unless you really need the wider tire in back for traction, I sugest you match all four tires, and rotate front to back every 5-6K miles. You'll get more bang for the buck out of your tire investment. Happy motoring!
I like the profile of the stock tires just want a hell of a lot more meat!!!

Stock = Whopper Jr. which is all good.
295/45-18 = 32oz Porterhouse!!!