Offset Backspacing?

[Brightlights]

Recently purchased 2012 E350 xlt with stock 245/75 16.

Im doing the Ford-plus 2" leveling kit, moving up to 265/75 16 and getting new alloy wheels. Research tells me i am currently at 0 offset but sales rep tell me the OEM 245's are +6 offset.

Anyone know if new wheels with -6 offset and 265/75 16 Patagonias will cause clearance issues in front or back of wheel well??

[motovan_mn]

You need to provide more info. Offset only tells you the distance from the mounting face of the wheel to the centerline of the wheel. Knowing the width of the old and new rims will let you figure out where the inner/outer faces of each rim will be.

All that being said, seems like a minor jump in tire size and offset so doesn't seem like it will be a problem.

Have you tried searching on this forum? There are tons of tire size threads already.

Just as an example:
https://www.sportsmobileforum.com/fo...2wd-14997.html

[posplayr]

Originally Posted by Brightlights

Recently purchased 2012 E350 xlt with stock 245/75 16.

Im doing the Ford-plus 2" leveling kit, moving up to 265/75 16 and getting new alloy wheels. Research tells me i am currently at 0 offset but sales rep tell me the OEM 245's are +6 offset.

Anyone know if new wheels with -6 offset and 265/75 16 Patagonias will cause clearance issues in front or back of wheel well??

I'm pretty sure if you increase the rim width by 1" (from stock) then you will need -12mm offset to keep the rim centered.

1" = 25.4 mm and the extra width would push the centerline out 12mm unless the new wheel is inset inboard.

Therefore you need -12mm to maintain a centerline for each 1" increase from the stock width. Of course, there is only so far you can go with an oversized tire.

Here is a recent thread on a similar topic

https://www.sportsmobileforum.com/fo...ils-31321.html

[Brightlights]

thanks for the replies and links. I had seen some of those threads and found them use full in some ways, but i still did not get the concept of back spacing. I wound up finding a video on youtube that gave good visuals and I think i am heading in the right direction. Thank you.

[kevman]

265/75R16's on -6mm offset rims will rub slightly on the stock front bumper valence and pinch weld at full lock.

We have 0mm offset rims and the tires did rub slightly before trimming the pinch weld. A -6mm offset rim will rub a little worse at full lock since the outer edge is slightly further out. That said, the pinch weld is easy to trim and by the time you put the wheel liner back you'll never even know you did any trimming.

[Electric9]

I’m posting in an attempt to be helpful and not sound like a total moron so please correct me if I am wrong.

I changed my wheels from the factory 16 inch steel to 16 inch aluminum. The wheels look good but the style I chose(simulated bead locker look) required stick on weights on the inside of the wheel. The extra thickness of the aluminum wheel vs steel plus the weights on the inside left pretty much zero clearance around the brakes to the point I had to remove some caliper material to prevent rubbing.

Not sure if this is common or I have a weird van or extra thick wheels/weights. Just wanted to throw it out there. Maybe others with more knowledge can chime in with brake clearance issues or lack thereof. .

[posplayr]

Originally Posted by Electric9

I’m posting in an attempt to be helpful and not sound like a total moron so please correct me if I am wrong.

I changed my wheels from the factory 16 inch steel to 16 inch aluminum. The wheels look good but the style I chose(simulated bead locker look) required stick on weights on the inside of the wheel. The extra thickness of the aluminum wheel vs steel plus the weights on the inside left pretty much zero clearance around the brakes to the point I had to remove some caliper material to prevent rubbing.

Not sure if this is common or I have a weird van or extra thick wheels/weights. Just wanted to throw it out there. Maybe others with more knowledge can chime in with brake clearance issues or lack thereof. .

It is a pretty much-accepted fact that you can't do the 2008+ front disk upgrade (larger disk/rotors) without going to 17" wheels so things are tight with 16" wheels. I know i tried some 17" wheels but not sure if I also tried the stock 16". With aftermarket 16" wheels and stick-on weights may understandably have issues.

[kevman]

Originally Posted by Electric9

I’m posting in an attempt to be helpful and not sound like a total moron so please correct me if I am wrong.

I changed my wheels from the factory 16 inch steel to 16 inch aluminum. The wheels look good but the style I chose(simulated bead locker look) required stick on weights on the inside of the wheel. The extra thickness of the aluminum wheel vs steel plus the weights on the inside left pretty much zero clearance around the brakes to the point I had to remove some caliper material to prevent rubbing.

Not sure if this is common or I have a weird van or extra thick wheels/weights. Just wanted to throw it out there. Maybe others with more knowledge can chime in with brake clearance issues or lack thereof. .

Same thing happened to us - the stick on weights wouldn't clear the calipers. We opted to go for the weights that clamp onto the wheel lip instead of modifying the calipers. This was for a 2002 model year and not the 2008+ calipers mentioned above.

[JWA]

Originally Posted by posplayr

It is a pretty much-accepted fact that you can't do the 2008+ front disk upgrade (larger disk/rotors) without going to 17" wheels so things are tight with 16" wheels. I know i tried some 17" wheels but not sure if I also tried the stock 16". With aftermarket 16" wheels and stick-on weights may understandably have issues.

I did the 2008+ front disc upgrade using nothing but stock Ford parts and it works perfectly even with stock 16" steel wheels. Here's my original write-up with a few photos included: https://www.sportsmobileforum.com/fo...tos-11255.html

[shenrie]

Originally Posted by kevman

265/75R16's on -6mm offset rims will rub slightly on the stock front bumper valence and pinch weld at full lock.

Blanket statements like this aren’t good. You should specifically state “on my van” in front of the quoted text above. There is so much variance in the vans (even more so on the 4wd converted vans) that stating what you did then having an uninformed person buy stuff on this statement would put you in a position of wasting their money. Do you have the lift the op is planning on using? Another variance... plus there is no industry standard to tire sizing, since your 265/75r16 tire could be an inch narrower and a .5” less overall diameter than the op’s same sized tire.

It’s a pita, but op should take everything read with a grain of salt and use the info in these types of threads as a rough guideline. If your trying to fit the most rubber as possible, your best asset is a friendly wheel and tire center willing to help test fit a few different sizes to get you where you want to be.