Okay, Since the first backspacing thread I made years ago is getting a little long and confusing with all the edits and questions in it, I'll start fresh here. Here goes.
First thing, the Bolt pattern on an S10 is 5 x 4 3/4"
OR
if you measure it out in metric, the design is 5 x 120.65mm.
Many people ask if a 5 x 120mm wheel will fit.. if you want to be picky, no, it's not the correct size, but yes, they do physically fit on the vehicle. DO not hold me personally nor S10forum.com responsible if your wheel studs break from running a wheel with this 5 x 120mm pattern to them.. saw it firsthand happen to a buddy of mine while driving 70mph down the highway
Measuring a 5-lug wheel is different than 4, 6, or 8-lug wheels. For the five lugs, you measure from the far side of the one lug hole to the center of the 3rd hole.
![Image]()
Now on to the offset and backspacing info. To make this as simple as possible, offset and backspace values can be interchangeable... if that makes any sense to you, if not read on. :haha:
Offset is the distance of the mounting flange to the rim's center. The offset of a wheel is measured with the following formula:
Offset = Backspace - (Rim Width)/2
(after you get your number, it will have to be converted to millimetres)
Tip. To convert from inches to mm, multiply by 25.4
To convert from mm to inches, divide by 25.4
Backspace is the distance from the mounting flange to the inside back edge of the rim.
If you only have the rim width, you can calculate either given the other. The easiest way to measure Backspace is to lay the wheel face down carefully, then lay a board or something flat across the back of the rim. The last measure down to the mounting flange; this will give you your backspacing number.
![Image]()
There are three different types of offset a wheel can have,
First is a Positive offset: This is where the mounting flange is positioned toward the front side of the wheel. This wheel style will have a large backspacing and is typical of the type of rim on most FWD cars. These WILL NOT fit a 2wd s10 unless you run an adapter to space the wheels out correctly.
Next is a Zero offset: This is where the mounting flange is positioned evenly with the center line of the rim. This is the style wheel a 2wd S10 requires for a stock fitment.
Lastly is the Negative offset: This style rim has the mounting flange shifted towards the back side of the edge towards the brakes. This wheel has a small backspacing, and so on; a 2wd S10 will push the wheels out of the wheel well further. On bagged or lowered trucks, you have to be careful, as there's a good chance the wheels won't tuck up inside the fenders.
When tightening the wheels down, make sure your finger pulls the lugs enough to center the wheel on the lugs, then go around and tighten them down in a crisscross pattern. This will center the wheel on the lug nuts without undue stress or unwanted vibrations.
![Image]()
Now finally, to the part everyone cares about. What fits? As I mentioned before, since the amount of backspacing and offset required to correctly tuck inside the fenders and do the track changes with the size and width of the rim, you have to pay attention, especially with smaller edges.
![Image]()
As you can see from the chart, the wider the wheel, the more significant the amount of backspacing you need to maintain close to a Zero offset.
Now keep in mind you can vary outside these numbers; this is only a suggested guideline. These measurements can be changed to a better fit with extreme drops, bags, and a body drop.
On smaller rims 14" - 17", you won't want to go much more positive offset than these numbers up front as you can run into rubbing issues on the outer tierod on the spindle steering knuckle.
7" wide - -12mm up to a +10mm offset
8" wide - -6mm up to a +10mm offset
8.5" wide - 0mm up to +6mm
On 18" and up rim sizes, you can increase the positive offset a little more since the inner lip of the rim will now clear the steering knuckle of the spindle.
7" wide - -12mm up to +6mm
8" wide - -6mm up to +15mm
8.5" wide - 0mm up to +15mm
9" wide - -6mm up to +15mm
I hope this helps and isn't too confusing. If anyone has any questions, feel free to post here or pm me. Also, I don't claim to know everything about wheels, so if you see something you disagree with, mention it.
First thing, the Bolt pattern on an S10 is 5 x 4 3/4"
OR
if you measure it out in metric, the design is 5 x 120.65mm.
Many people ask if a 5 x 120mm wheel will fit.. if you want to be picky, no, it's not the correct size, but yes, they do physically fit on the vehicle. DO not hold me personally nor S10forum.com responsible if your wheel studs break from running a wheel with this 5 x 120mm pattern to them.. saw it firsthand happen to a buddy of mine while driving 70mph down the highway
Measuring a 5-lug wheel is different than 4, 6, or 8-lug wheels. For the five lugs, you measure from the far side of the one lug hole to the center of the 3rd hole.
Now on to the offset and backspacing info. To make this as simple as possible, offset and backspace values can be interchangeable... if that makes any sense to you, if not read on. :haha:
Offset is the distance of the mounting flange to the rim's center. The offset of a wheel is measured with the following formula:
Offset = Backspace - (Rim Width)/2
(after you get your number, it will have to be converted to millimetres)
Tip. To convert from inches to mm, multiply by 25.4
To convert from mm to inches, divide by 25.4
Backspace is the distance from the mounting flange to the inside back edge of the rim.
If you only have the rim width, you can calculate either given the other. The easiest way to measure Backspace is to lay the wheel face down carefully, then lay a board or something flat across the back of the rim. The last measure down to the mounting flange; this will give you your backspacing number.
There are three different types of offset a wheel can have,
First is a Positive offset: This is where the mounting flange is positioned toward the front side of the wheel. This wheel style will have a large backspacing and is typical of the type of rim on most FWD cars. These WILL NOT fit a 2wd s10 unless you run an adapter to space the wheels out correctly.
Next is a Zero offset: This is where the mounting flange is positioned evenly with the center line of the rim. This is the style wheel a 2wd S10 requires for a stock fitment.
Lastly is the Negative offset: This style rim has the mounting flange shifted towards the back side of the edge towards the brakes. This wheel has a small backspacing, and so on; a 2wd S10 will push the wheels out of the wheel well further. On bagged or lowered trucks, you have to be careful, as there's a good chance the wheels won't tuck up inside the fenders.
When tightening the wheels down, make sure your finger pulls the lugs enough to center the wheel on the lugs, then go around and tighten them down in a crisscross pattern. This will center the wheel on the lug nuts without undue stress or unwanted vibrations.
Now finally, to the part everyone cares about. What fits? As I mentioned before, since the amount of backspacing and offset required to correctly tuck inside the fenders and do the track changes with the size and width of the rim, you have to pay attention, especially with smaller edges.
As you can see from the chart, the wider the wheel, the more significant the amount of backspacing you need to maintain close to a Zero offset.
Now keep in mind you can vary outside these numbers; this is only a suggested guideline. These measurements can be changed to a better fit with extreme drops, bags, and a body drop.
On smaller rims 14" - 17", you won't want to go much more positive offset than these numbers up front as you can run into rubbing issues on the outer tierod on the spindle steering knuckle.
7" wide - -12mm up to a +10mm offset
8" wide - -6mm up to a +10mm offset
8.5" wide - 0mm up to +6mm
On 18" and up rim sizes, you can increase the positive offset a little more since the inner lip of the rim will now clear the steering knuckle of the spindle.
7" wide - -12mm up to +6mm
8" wide - -6mm up to +15mm
8.5" wide - 0mm up to +15mm
9" wide - -6mm up to +15mm
I hope this helps and isn't too confusing. If anyone has any questions, feel free to post here or pm me. Also, I don't claim to know everything about wheels, so if you see something you disagree with, mention it.
