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Offset question with 37x13.50 X 18 tires

Tlpollock

Tlpollock

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I am researching 18x9 wheels to go on a 3500 SRW Mega. I love the way a -12 offset looks but I am open to -6,0,+1 or +6 offsets.
I am wanting to know which of the offsets would require the least amount of trimming to fit the 37x13.50 x 18’s.
I prefer the fat look of 13.50’s on a mega cab, but will go with 12.50’s if a lot of work is needed to fit wide tires.
I am plan on a 1.75 inch Thuren level kit with sway bar, resi front fox 2.0’s and 2.0 slicks in the rear. A two inch bag spacer with a 2 inch block.
I do hope this setup will look good , anyone have this setup?
I’m looking at Falken RT01 tires also.
 
Hey Buddy ! I have a 2020 Megacab with a 2.5 Carli backcountry leveling kit. Method 20x9 with a -12 offset and 37x 13.50-20 Nitto Ridgegrapplers.I just had to trim the back plastic on front fenders. I wouldn’t go with anything with a positive offset unless you want the tires underneath the truck more.A 1.75 leveling kit may not be big enough to fit 37s but will definitely fit 35s. CJC off-road has a YouTube video on what it takes the fit 37s. I hope this helps!
 
Johnny B said:
Hey Buddy ! I have a 2020 Megacab with a 2.5 Carli backcountry leveling kit. Method 20x9 with a -12 offset and 37x 13.50-20 Nitto Ridgegrapplers.I just had to trim the back plastic on front fenders. I wouldn’t go with anything with a positive offset unless you want the tires underneath the truck more.A 1.75 leveling kit may not be big enough to fit 37s but will definitely fit 35s. CJC off-road has a YouTube video on what it takes the fit 37s. I hope this helps!
Click to expand...
This is simply not true. Stock wheels are a +54mm offset meaning even if he went to a +1 offset the outside of the wheel would be over 2” further out lol, meaning outside the fender.

To the op. +6 will fit best of what you asked about anyway. But, with that said the experts like CJC and anyone on this site will tell you a x9 with +18 offset is perfect for fitting big tires with ease.
 
I have 35 12.50R17 on stock rims on our 2016 Ram 2500 4x4 PW with very slight rubbing at full lock turns with the Toyo C/T's. On our 2024 Ram 3500 4x4 SRW one could go even narrower to a 37 11.50R18 size. The same 3,860 lb maximum load as the OEM sized 275 70R18 Toyo C/T's on it now. Narrower has a slightly better advantage here in the Rockies at plowing at higher speeds through snowdrifts versus riding up on top, so a 35 11.50R17 on our PW I would still prefer. Ground clearance is a plus with the taller tires.
Screenshot_20250125-101444_Chrome.jpg
 
Vdrsnk said:
This is simply not true. Stock wheels are a +54mm offset meaning even if he went to a +1 offset the outside of the wheel would be over 2” further out lol, meaning outside the fender.

To the op. +6 will fit best of what you asked about anyway. But, with that said the experts like CJC and anyone on this site will tell you a x9 with +18 offset is perfect for fitting big tires with ease.
Click to expand...
After watching a few CJC videos, it appears they prefer +18 to +25 ish and fit 37’s. I am looking harder at the +18 or + 20’s now after watching CJC videos.
Something about the way a megacab looks on 13.5 ‘s catches my eye. I have never had 13.5’s, always been a 35x12.50 guy . I think the 37’s look better now. I see the 13.50’s are even cheaper than the 12.50’s ?
 
Johnny B said:
Hey Buddy ! I have a 2020 Megacab with a 2.5 Carli backcountry leveling kit. Method 20x9 with a -12 offset and 37x 13.50-20 Nitto Ridgegrapplers.I just had to trim the back plastic on front fenders. I wouldn’t go with anything with a positive offset unless you want the tires underneath the truck more.A 1.75 leveling kit may not be big enough to fit 37s but will definitely fit 35s. CJC off-road has a YouTube video on what it takes the fit 37s. I hope this helps!
Click to expand...
I love the way that -12 looks, but it appears that it takes more trimming to fit especially with 13.5 wides.
I have learned that the fender well is convex and pushing too far in the negative (outward) direction will actually reduce clearance.
 
My son in law is running 13.5's on his 4th gen. Carli 3.5" on a 17" wheel. Inner fender timed. Not sure his offset though.
IMG_8152.JPG

2.75" Thuren leveling kit on mine. 12.50's on a 18x9 +18 offset. Minimal work on the inner fender to clear at lock.
IMG_7722.JPG
 
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