What is Difference Between -18 Offset & OEM Wheels And 1.75" Spacers?

[CarbonSteel]

Thanks for this. I only added spacers to the OEM wheels because the inner wheel would rub on the tie-rod at full lock after I installed some Metal Cloak front end upgrades. MC said it has happened a few times due to variations in FCA's manufacturing.

An additional 1.19" is a little more than I want to have sticking out. It sounds like I need to look at 0 offset or -12 at the most but I would also need to check the clearance on the tie-rod. I tried adding washers under the steering stops, but it was not enough clearance. I guess I could look at installing slightly longer steering stops.

@MonopoliJLUR - can you check my thoughts on this:

OEM Wheel = +44.5 (offset) + 44.5 (spacer) = 89 total offset
After Market Wheel = -6 (offset) + 44.5 (OEM offset) + 12.7 (extra wheel width) = 63.2 total offset

If this is correct, then choosing a wheel with -6 offset and removing the spacer will have the tires sticking out about 1" less than what I currently am.

Did I forget to add something in?

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[blnewt]

On that web link I posted above they also have backspacing listed in their specs.

 

[Hucke_250]

@MonopoliJLUR - can you check my thoughts on this:

OEM Wheel = +44.5 (offset) + 44.5 (spacer) = 89 total offset
After Market Wheel = -6 (offset) + 44.5 (OEM offset) + 12.7 (extra wheel width) = 63.2 total offset

If this is correct, then choosing a wheel with -6 offset and removing the spacer will have the tires sticking out about 1" less than what I currently am.
Did I forget to add something in?

For the -6 offset wheel, what is the wheel width?
What size tires are you currently running and what size are you getting for the aftermarket set up?
Your current setup with spacer factored in is 17x7.5 offset 0.

 

[CarbonSteel]

For the -6 offset wheel, what is the wheel width?
What size tires are you currently running and what size are you getting for the aftermarket set up?
Your current setup with spacer factored in is 17x7.5 offset 0.

8.5" for the rim width and 315/70/17 for the tires which remain the same. How is it offset zero on the current setup?

 

[Hucke_250]

8.5" for the rim width and 315/70/17 for the tires which remain the same. How is it offset zero on the current setup?

The -6 offset wheel will stick out an addition 3/4 inch further than the current set up

 

[GATORB8]

8.5" for the rim width and 315/70/17 for the tires which remain the same. How is it offset zero on the current setup?

Your spacer counteracts the stock offset. +44.5 (stock offset) - 44.5 (spacer) = 0 net offset

 

[Mx5red]

@MonopoliJLUR - can you check my thoughts on this:

OEM Wheel = +44.5 (offset) + 44.5 (spacer) = 89 total offset
After Market Wheel = -6 (offset) + 44.5 (OEM offset) + 12.7 (extra wheel width) = 63.2 total offset

If this is correct, then choosing a wheel with -6 offset and removing the spacer will have the tires sticking out about 1" less than what I currently am.

Did I forget to add something in?

If the OEM wheel is +44.5 that means the mounting surface is +44.5 (out) from the midline of the wheel, and tucks the OEM wheels in under the fenders. You mean to add a (-) 44.5 spacer for a total 0 offset. As others have mentioned that doesn't tell you anything about how far it pokes out. You need to factor in wheel width as well (usually add an inch and divide by two, convert to metric).

By far the easiest way to figure this out is to play around with the calculators @blnewt mentioned

 

[MonopoliJLUR]

@MonopoliJLUR - can you check my thoughts on this:

OEM Wheel = +44.5 (offset) + 44.5 (spacer) = 89 total offset
After Market Wheel = -6 (offset) + 44.5 (OEM offset) + 12.7 (extra wheel width) = 63.2 total offset

If this is correct, then choosing a wheel with -6 offset and removing the spacer will have the tires sticking out about 1" less than what I currently am.

Did I forget to add something in?

think of the positive offset as it being farther in, positive means the mounting surface is farther forward from the centerline while negative is farther back, so the more negative the farther it will stick out

so +44 offset to -6 offset is essentially sticking 50mm farther out then taking out the 44.5 mm spacer will tuck them back in that much so basically it’ll be about 6mm + the extra wheel width (12.7mm) so about 19mm farther out

 

[GATORB8]

If the OEM wheel is +44.5 that means the mounting surface is +44.5 (out) from the midline of the wheel, and tucks the OEM wheels in under the fenders. You mean to add a (-) 44.5 spacer for a total 0 offset. As others have mentioned that doesn't tell you anything about how far it pokes out. You need to factor in wheel width as well (usually add an inch and divide by two, convert to metric).

By far the easiest way to figure this out is to play around with the calculators @blnewt mentioned

He's using the same tires though, so the tire poke isn't equal to the wheel poke. Let's say he gains .4" in section width from going to an inch wider wheel on the 315s, so the outside face of the tire will be .2" (~5mm) further out if he uses matching 0 offset 17x8.5s, also the tire will be .2" closer to his suspension.
-18 mm offset wheels with no spacers will be 18mm out from the wheel center and 5mm out from the tire getting fatter on the rim, so 23mm further out on the outside sidewall, and 13mm further out on the inside sidewall.
In reality, unless OP is super close to rubbing, 5mm is negligible. So if he wants the same stance, he needs a 0 offset

 

[CarbonSteel]

He's using the same tires though, so the tire poke isn't equal to the wheel poke. Let's say he gains .4" in section width from going to an inch wider wheel on the 315s, so the outside face of the tire will be .2" (~5mm) further out if he uses matching 0 offset 17x8.5s, also the tire will be .2" closer to his suspension.
-18 mm offset wheels with no spacers will be 18mm out from the wheel center and 5mm out from the tire getting fatter on the rim, so 23mm further out on the outside sidewall, and 13mm further out on the inside sidewall.
In reality, unless OP is super close to rubbing, 5mm is negligible. So if he wants the same stance, he needs a 0 offset

With the OEM wheels and no spacer, I am rubbing my inner wheel rim against the tie-rod at full lock. It sounds like if I go 0 offset although the tire poking out from the fender would be close to same, the additional 1/2" gained from the increase of the new wheel width would cause the inner rim to hit the tie-rod even sooner than full lock.

Am I thinking about this in the correct way?

 

[GATORB8]

With the OEM wheels and no spacer, I am rubbing my inner wheel rim against the tie-rod at full lock. It sounds like if I go 0 offset although the tire poking out from the fender would be close to same, the additional 1/2" gained from the increase of the new wheel width would cause the inner rim to hit the tie-rod even sooner than full lock.

Am I thinking about this in the correct way?

At zero offset and the 1/2” additional wheel width in each direction, you’ll still be about an inch further out to inside face of wheel rim than stock with no spacer.

 

[CarbonSteel]

At zero offset and the 1/2” additional wheel width in each direction, you’ll still be about an inch further out to inside face of wheel rim than stock with no spacer.

Thanks @GATORB8 + @blnewt + @MonopoliJLUR + @Chocolate Thunder and those I missed for taking the time to answer all of my questions--it is much appreciated!

 

[CarbonSteel]

@MonopoliJLUR + @blnewt + @GATORB8 + @Chocolate Thunder - just need your confirmation. Based upon this calculator, I think that a 0 or -6 offset would have me as close as possible to my current set up.

What say you?

0 Offset:

-6 Offset:

-12 Offset:

-18 Offset:

 

[MonopoliJLUR]

He's using the same tires though, so the tire poke isn't equal to the wheel poke. Let's say he gains .4" in section width from going to an inch wider wheel on the 315s, so the outside face of the tire will be .2" (~5mm) further out if he uses matching 0 offset 17x8.5s, also the tire will be .2" closer to his suspension.
-18 mm offset wheels with no spacers will be 18mm out from the wheel center and 5mm out from the tire getting fatter on the rim, so 23mm further out on the outside sidewall, and 13mm further out on the inside sidewall.
In reality, unless OP is super close to rubbing, 5mm is negligible. So if he wants the same stance, he needs a 0 offset

With the OEM wheels and no spacer, I am rubbing my inner wheel rim against the tie-rod at full lock. It sounds like if I go 0 offset although the tire poking out from the fender would be close to same, the additional 1/2" gained from the increase of the new wheel width would cause the inner rim to hit the tie-rod even sooner than full lock.

Am I thinking about this in the correct way?

@MonopoliJLUR + @blnewt + @GATORB8 + @Chocolate Thunder - just need your confirmation. Based upon this calculator, I think that a 0 or -6 offset would have me as close as possible to my current set up.

What say you?

0 Offset:

-6 Offset:

-12 Offset:

-18 Offset:

I think whoever said something about using the same tires is right and that the extra wheel width won’t affect it too much since the tire is out further anyway, so I think 0 offset will be almost the same as you have now and any more negative offset from there will just add that much more poke

I’d go 0 offset (that’s what I’m going to be doing on my Jeep when it comes)

 

[Chocolate Thunder]

If you’re trying to keep suspension clearance and minimize poke, I think I’d choose the -6. Are all of those offset options available on the wheels you want?

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