wheel/tire combo

[john h]

I think I have narrowed all my choices down.  I think they will fit but want to post the combo just to be sure.   


front: 215-55-17    wheel 17x7 5x114.3 zero offset  72.7 bore (Brand/style) Rev 105)
Rear: 255-50-17     Wheel 17x8 5x114.3 zero offset  72.7 bore (brand/style Rev 105)

Should I keep the profile front to back the same?? 

Thanks for any info.
John

[72bluNblu]

If the tire width varies, don't worry about the profile number being the same. The profile number is the tire's sidewall height, but it's listed as a % of the width. So, wider tires have taller sidewalls for a given profile. To work out the sidewall height, you multiply the tire width by the percentage of the profile. To get the total height of the wheel, you double the sidewall height and add the rim diameter.

So...
215/55/17 works out to be 215mm X.55 = 118.25mm, which is your sidewall height . Multiply by two to get the height top and bottom 118.25x2= 236.5mm. Convert to inches and add 17" and you get 26.3", which is the height of your wheel.

A 255/50/17 has a sidewall height of 255mm x. 5 = 127.5mm, so even though it's a "lower" profile its a taller tire. Total wheel height is 27".

So, even though the front tire has a higher profile, it has a smaller sidewall and is a shorter wheel.

As far as them fitting, they should. I wouldn't go any taller for a wheel in the front, as you'll end up with clearance issues. But a 215 is an easy fit on the front. In the back a 255 should be no problem either, 27" is fairly tall but typically anything less than 28" tall fits without issues.

You could actually run wider tires both front and rear. I have 17x9's with zero offset on my Challenger, with 275/40/17's on the front and rear. That's pretty much the limit for width for the front, and the back too unless you have some kind of spring offset installed. If you wanted to you could run 255/45/17's on 17x8's (or 17x9's) all the way around and be able to rotate your tires.

These are my rims...

http://www.summitracing.com/parts/vsw-141h7965gm0/overview/

[john h]

If the tire width varies, don't worry about the profile number being the same. The profile number is the tire's sidewall height, but it's listed as a % of the width. So, wider tires have taller sidewalls for a given profile. To work out the sidewall height, you multiply the tire width by the percentage of the profile. To get the total height of the wheel, you double the sidewall height and add the rim diameter.

So...
215/55/17 works out to be 215mm X.55 = 118.25mm, which is your sidewall height . Multiply by two to get the height top and bottom 118.25x2= 236.5mm. Convert to inches and add 17" and you get 26.3", which is the height of your wheel.

A 255/50/17 has a sidewall height of 255mm x. 5 = 127.5mm, so even though it's a "lower" profile its a taller tire. Total wheel height is 27".

So, even though the front tire has a higher profile, it has a smaller sidewall and is a shorter wheel.

As far as them fitting, they should. I wouldn't go any taller for a wheel in the front, as you'll end up with clearance issues. But a 215 is an easy fit on the front. In the back a 255 should be no problem either, 27" is fairly tall but typically anything less than 28" tall fits without issues.

You could actually run wider tires both front and rear. I have 17x9's with zero offset on my Challenger, with 275/40/17's on the front and rear. That's pretty much the limit for width for the front, and the back too unless you have some kind of spring offset installed. If you wanted to you could run 255/45/17's on 17x8's (or 17x9's) all the way around and be able to rotate your tires.

These are my rims...

http://www.summitracing.com/parts/vsw-141h7965gm0/overview/

Thanks for the breakdown.  it confirms I was doing the math correctly.  I was more curious about the opinion of seeing the 55 up front and the 50 in back.  based on tire width the profile would be 5" tall in back and 4.65" tall up front.  I guess when I break it down it's only 3/8" taller from bottom to rim or so, probably won't look bad if you notice it at all.  now the whole works being 3/4" taller total diameter is that going to detract from a good looking wheel and tire combo???  This is such a hard decision.  it's a lot of money spent.

[chargerdon]

I have disc brakes on the front, drums on the rear.With a 17x8 wheel, what is the maximum POSITIVE offset that will fit the front and rear .   I have disc brakes on the front, drums on the rear.  There is a set of 17x8 wheels with 235/50/17 tires on them with a stated +42 offset.   Will these fit or will the +42 offset hit the suspension?? 

[72bluNblu]

I have disc brakes on the front, drums on the rear.With a 17x8 wheel, what is the maximum POSITIVE offset that will fit the front and rear .   I have disc brakes on the front, drums on the rear.  There is a set of 17x8 wheels with 235/50/17 tires on them with a stated +42 offset.   Will these fit or will the +42 offset hit the suspension??

Not even close. With a 17" rim you can still get interference with the outer tie rod. My 17x9's with 5" of backspace have less than a 1/4" to the outer tie rod. I would say the max backspace you can safely run with most 17" rims is probably 5 1/8", so for a 17x8" that works out to a +15 offset. Any 17x8 with more offset than that will probably need a spacer to make up the difference. So, you could run a 17x8" with a 20mm offset, but you'd probably need a 5mm spacer. Obviously some of that will differ with rim design, suspension tolerances etc, but for a 17x8 I would use +15 as my benchmark, assuming that if I went beyond that I would need a spacer to get back to +15.

[chargerdon]

Thanks for the info on wheel spacing.   Help me out some more here.   I currently have 14" aftermarket wheels with 4 badly dry rotted tires.   So, i need new tires, but, you simply cant find any good "bargains" for large width rubber (225 or 235) tires for 14 inch rims.   BFG new tires in 235x60x14 cost $135 apiece and there aren't many "cheap brands" in those sizes.    So thinking of replacing the wheels.   

I want good tread width for traction but don't want to screw up the tire circumference to hurt the effective axle ratio.   Originals were 25" height so want to stick to the 25-26" height.   So, looking at finding 16 or 17 inch rims and putting on something like 225 or 235 50 series tires.   If i go with 16 rims what is a good width to buy, and same question for 17"...what width to put on 225 or 235 rubber??   7"  7.5" or 8" ??   

[dodj]

  I was more curious about the opinion of seeing the 55 up front and the 50 in back. 

I have 40 up front and 35 on the back, but they have close to the same sidewall height.
IMO, if you have differing width tires, you need to use different series rubber to make them match up.