suggested offset for 17's

hey guys, im looking for some new wheels and just was wondering what you guys are running for offset or backspace. Im looking at 17x9 or 17x8.5.
Probably gonna run 265/70/17 or 285/70/17 duratracs.

I was told by a local shop that i should get 17x8.5 for 265 with +15 offset which is like 5.5" backspace for a flush look. Same rim comes in a -6 offset or 4.5" backspace but the guy said it would hang out like 2".

I dont wanna put extra stress on my components but would like it to hang out a little. thanks for the help.

 

Backspacing depends on rims width and offset.. If you want to run the 285/70/17's, you need 4.5" of backspacing, which would be -12mm offset on a 9" wide rim, and -6mm offset on an 8.5" rim.

The 8.5" rim would stick out 2.5" further than stock, while the 9" rim would stick out 3" further than stock.

 

thanks. so what backspacing would you suggest for 265's. isn't the stock backspacing like 5.5"?

 

Yep for 265's you can run anywhere between 4.5 and 5.5" backspacing.

 

so im looking at the atx thugs and these are the options for that wheel. which size would you suggest for 265 and 285.

Size Offset Backspace

AX39917 17" x 8.5" -6 4.51 6x139.7

AX39917 17" x 8.5" 15 5.34 6x139.7

 

You can prolly do the +15 offset on the 265s. But for 285s to clear the UCA you'll need 0 or -6mm offset.

 

I suggest the first one. You can run 265's on it, and if you decide to get a lift and go with 285's down the road, you won't need new rims.

 

awesome thanks for the help guys.

 

Was just thinking about this the other day..

So with that one, how much will 265s stick out from what it is now?

 

Less than an inch.

 

They will stick out 2.5" more than stock, because they have 1" less backspacing and are also 1.5" wider than stock.

 

You did not take rim width into account.

 

Hmmm.. then if down the road you go with 285s then they will be around 3" or so....

 

The tires are the same width, tho. Mounted up on the wider rim, they'll be a little wider, but not a full 1.5"

Also, you're double adding. Only half of the increased width is to the outside.

Change in "stick-out-ness" = change in negative offset, plus 1/2 increase in width of mounted tire on rim.

Change in "stick-IN-ness" = change in positive offset, plus 1/2 increase in width of mounted tire on rim.

Still, you're right, I didn't account for increase in mounted width. I'll re-evaluate and say "a little MORE than an inch."

 

We may also be making different assumptions about what the stock factory wheel offset is. I've never seen a number I'm entirely convinced is correct. Have you?

 

i was told the stock rim is something like 17x7 +30 offset and like 5.5" offset.

SO... if i want 265's on the 17x8.5 to stick out about 1 inch more than stock what rim should i choose?

I definatly dont want the new tires to hang out 3".

I was hoping to get 265's to stick out a little more than stock to appear wider but keep my gas mileage down by keeping a narrower tire.

I thought that if the stock rim is 7" wide with 5.5" backspace it will stick out 1.5".

If a rim is 8.5" wide with 4.5" backspace it will stick out 3.5". Which is 2" more than stock.

I thought that backspace was a simple measurement of the rims actual space from the back of the mounting face to the inner edge of the rim. So backspacing is not dependant on rim width.. this is why i need some clarification. thanks

 

I'm not double adding, because if you add 1/2 the width to the front, and 1/2 to the back, then you are changing the backspacing of the rim.

Adding to both sides of the rims will keep the offset the same, not the backspacing. So in order to keep the distance from the rim mounting surface to the back of the rim constant, all of the additional width must be added to the outside of the rim.

So the outer edge of the rim will be 2.5" further out than stock.

 

You are right, it is a very simple measurement. What I should have said was in order to calculate backspacing, rather than directly measuring it, you would need both offset and rim width. If you just have the offset, you can't calculate backspacing without knowing the width.

 

If we take that as a given, I don't disagree with KPTs numbers and how he calculates them - except for one small quibble:

He's talking about how far the RIMS stick out.

I'll say, yeah, but the 265 width TIRES won't bulge out as far past the rims as they do on the stock wheel. So the TIRE will stick out a little less than his total - to the tune of, say, half an inch.